JPH11184557A - Method and device for supporting time change and mechanically readable recording medium for recording program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately perform time correction by preventing an adverse influence from being exerted upon time correspondent processing even when an internal generated time is discontinuous by the time correction at a device with a clock function having a time generating means inside the device to perform the processing based on the generated time. SOLUTION: Based on the time period from an input device 1, a time changing means 3 immediately corrects the time of a time generating means 7. When the time is advanced by the time correction, a time change discriminating means 4 discriminates that a blank generates in the time and when the time is delayed, discriminates that overlap generates in the time. According to this discriminated result, a time correspondent processing control means 8 speedily starts the time correspondent processing to be started in the time zone becoming the blank and when the overlap in the time occurs, the means 8 is controlled so as not to double start the time correspondent processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device with a clock function having a time generating means in the device and performing a time corresponding process based on the generated time, and more particularly to a device for immediately performing time correction and performing time correction. The present invention relates to a technique for preventing an adverse effect due to discontinuous time.

[0002]

2. Description of the Related Art In an apparatus such as a computer system, a predetermined process is often executed in a predetermined time zone. The processing that is performed at a regular time in this manner is referred to as time corresponding processing. For this reason, a computer system or the like is provided with a time generating means inside, and monitors the arrival of a processing execution timing based on the time instantly generated by the time generating means. Therefore, if the time indicated by the time generating means is different from the actual time, the execution time of the time corresponding processing will not be accurate. Therefore, in order for the time generating means to always keep the correct time, an accurate time is input from the outside to correct (correct) the time of the time generating means on a regular basis.

By the way, there is a process A to be executed in a time zone from 18:00 to 59 seconds, for example, and the time is corrected when the time indicated by the time generating means is 17:58:00. 18: 02: 0 which is the exact time
When proceeding to 0 seconds, as shown by the arrow in FIG.
The time of the time generation means is changed from 17:58:00 to 18:00
If the time is corrected to 2:00 seconds, a time gap of 4 minutes indicated by a broken line occurs, and there is a possibility that the process A is not performed. Also,
For example, there is a process B to be performed in the time zone from 20:00:00 to 59:02, and the time indicated by the time generating means is correct by performing time correction at 20: 02: 00: 00. In the case of delaying at 19:59:00, FIG.
As shown by an arrow in FIG.
If you correct the time from 0:20:00 to 19:59:00, the time overlap occurs for 3 minutes when the arrows overlap,
There is a possibility that the process B that has been already performed immediately before the time correction is performed again after the time correction.

For this reason, in a device with a clock function that has a time generating means in the device and performs processing based on the generated time, some technique for preventing the adverse effect of time correction is required.

[0005] One of the prevention techniques is disclosed in Japanese Patent Application Laid-Open No. 5-536.
There is a technique proposed in Japanese Patent Application Publication No. 84-84. With this technology,
If there is an instruction to change the internally generated time from the outside, instead of changing it immediately, spend a certain amount of time and advance the time faster than usual, or advance the time slower than usual, and after a certain amount of time elapses The continuity of the internally generated time is guaranteed by finally completing the time adjustment at the time.

[0006]

However, in the above-mentioned prior art, the time is changed by spending a certain time to advance the time faster than usual or conversely to advance the time slower than usual. Even if it is instructed, it cannot be corrected to an accurate time until a certain time has elapsed. The longer the time required until the time is corrected to the correct time, the later the improvement in the decrease in accuracy of the execution time of the time corresponding processing is delayed.

Accordingly, an object of the present invention is to provide a device with a clock function that has time generating means in the device and performs processing based on the generated time even if the internally generated time becomes discontinuous due to time correction. An object of the present invention is to make it possible to correct time instantly by not affecting the time correspondence processing.

[0008]

In order to achieve the above object, the time change support method of the present invention has a time generating means in an apparatus, and performs processing based on the time indicated by the time generating means. In the device with a clock function, when the time of the time generating unit is corrected based on a time given from the outside, based on the time indicated by the time generating unit immediately before the time correction and the time when the time is corrected. In addition, the promotion of the execution of the process linked to the time or the suppression of the execution is controlled. Specifically, a time changing step of correcting the time of the time generating means based on a time given from outside,
When the time of the time generating means is advanced by the time changing step, a step of promptly performing a process to be performed from the time indicated by the time generating means immediately before time correction to the time corrected by the time changing step And when the time of the time generating means is delayed by the time changing step, performing processing to be performed from the time corrected by the time changing step to the time indicated by the time generating means immediately before the time correction. And a step of inhibiting.

Further, in order to achieve the above object, the time change support device of the present invention is a device with a clock function which has a time generating means in the device and performs processing based on the time indicated by the time generating means. A time changing unit that corrects the time of the time generating unit based on a time given from outside; and, when the time of the time generating unit is advanced by the time changing unit, the time generating unit indicates the time immediately before the time correction. When the time to be performed from the time when the time has been corrected by the time changing means is promptly performed, and the time of the time generating means is delayed by the time changing means, the time corrected by the time changing means is And a time corresponding processing control means for suppressing execution of processing to be performed by the time indicated by the time generation means immediately before time correction.

[0010] In the time change support device of the present invention configured as described above, when the correction time is given from the outside,
The time changing means immediately corrects the time indicated by the time generating means based on the time. Then, when the time of the time generating means is advanced, the time corresponding processing control means performs the time from the time indicated by the time generating means immediately before the time correction to the correction time, that is, during the blank time zone of the internally generated time. When the time of the time generation means is delayed by time correction, the time of the time generation means is delayed by time correction by causing the processing to be performed quickly, and conversely, from the correction time to the time indicated by the time generation means immediately before the time correction , That is, during the overlapping time period of the internally generated time, the execution of the process is suppressed, thereby preventing the double execution.

The time change support device of the present invention has time generation means in the device so as to achieve the above object and to investigate what time correction has been performed in the past. In a device with a clock function that performs processing based on the internally generated time of the time generation unit, an external time input unit that inputs a time from outside the device, and an internally generated time indicated by the time generation unit is output by the external time input unit. Time changing means for correcting to the input external input time, time difference calculating means for calculating the difference between the external input time externally input in the external time input means and the internally generated time generated in the time generating means, Time change determining means for analyzing the time difference calculated by the time difference calculating means to determine how much the internally generated time has been advanced or delayed; Based on the determination result of the change determination unit, a time corresponding processing control unit that controls execution suppression or execution promotion of the process linked to the time, information of the determination result of the time change determination unit, information of the internally generated time, and Time change history information generation means for generating time change history information including information on an external input time; and time change history information storage means for storing time change history information generated by the time change history information generation means. ing.

In the time change support apparatus of the present invention thus configured, when a user inputs a correction time from outside the apparatus, the external time input means inputs the time, and the time change means outputs the time generation means. Is immediately corrected to the input externally input time. At this time, the time difference calculation means calculates a difference between the external input time and the internally generated time (time immediately before correction) internally generated by the time generation means, and the time change determination means analyzes the calculated time difference, It is determined how much the internally generated time has been advanced or delayed. Then, the time corresponding processing control means controls the execution suppression or the promotion of the execution of the processing linked to the time based on the determination result, and the time change history information generating means outputs the information of the determination result and the information of the internal generation time. And generating the time change history information including the information of the external input time and storing the generated time change history information in the time change history information storage means.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. The device with a clock function 10 of this example includes an external time input means 1, a time difference calculation means 2, a time change means 3, a time change determination means 4, a time change history information generation means 5, a time change history information The storage device includes a storage unit 6, a time generation unit 7, a time correspondence processing control unit 8, and an execution history information storage unit 9. FIG. 2 is a flowchart showing an outline of the processing of the device 10 with a clock function. In the case where the device with a clock function 10 includes a computer such as a microprocessor as a control device, each of the above units can be realized by hardware (a CPU, a memory, and the like) of the computer and a program. In this case, as shown in FIG.
A recording medium 13 storing a program for a computer constituting the device 10 with a clock function is provided. Storage medium 13
The program inside is read by a computer, and by controlling the operation of the computer, external time input means 1, time difference calculation means 2, time change means 3, time change determination means 4, time change history information The generating means 5, the time generating means 7, and the time corresponding processing control means 8 are realized.

The time generating means 7 is a clock inside the apparatus, and keeps time every moment. This time generation means 7
Is given to the time difference calculating means 2 and is notified to the time corresponding processing control means 8 by interruption at a predetermined cycle, for example, 10 seconds, 1 minute, or the like. The time of the time generating means 7 can be corrected by the time changing means 3.

The external time input means 1 is a means for inputting a correction time from the input device 11. The user can use the input device 1
After inputting the correction time using, for example, a ten key on the display device 1 and confirming the content by the monitor display of the display device 12, when the time change start key on the input device 11 is pressed at the timing when the correction time is reached, the timing Then, the external time input means 1 inputs the corrected time and transmits it to the time difference calculating means 2 as the external input time (step 1-1).

The time difference calculating means 2 comprises an external time inputting means 1
When the external input time is received from the device, the current time of the time generation means 7 is read as the internal generation time, and the internal generation time is subtracted from the external input time to obtain a time difference between the two.
The information is transmitted to the time changing means 3 together with the external input time and the internally generated time (step 2-1). The time difference has a positive value when the external input time is larger than the internally generated time, and has a negative value when the external input time is opposite.

When the time changing means 3 receives the external input time, the internally generated time, and the time difference between the two from the time difference calculating means 2, the time changing means 3 changes the time of the time generating means 7 to the external input time to generate the time. The time setting of the means 7 is performed, a time setting completion message is displayed on the display device 12, and the external input time, the internally generated time, and the time difference between the two are notified to the time change determining means 4 (step 3-1).

When the time change judging means 4 receives the external input time, the internally generated time and the time difference between the two from the time changing means 3, it analyzes the time difference and determines how much the internally generated time has been advanced or delayed. (Step 4
-1) The following processing is performed according to the determination result.

When the time difference is negative In this case, since the time of the time generation means 7 has been advanced by time correction, it is recognized that a time gap has occurred, and the time correspondence processing control means 8 And a time change notification specifying the external input time and the internally generated time are issued, and the time change history information generating means 5 is notified that the time difference of the time has been generated. The external input time and the internally generated time are notified.

When the time difference is positive In this case, since the time of the time generation means 7 has been delayed by the time correction, it is recognized that time overlap has occurred,
A time change notification specifying the occurrence of time overlap and the internal generation time is issued to the time correspondence processing control means 8, and the time difference of the time difference is notified to the time change history information generation means 5. Are notified of the occurrence of duplication and the above-mentioned external input time and internally generated time.

In the present embodiment, when the time difference is zero, the time difference is handled in the same way as when the time difference is negative, but may be handled in the same way as when the time difference is positive.

Each time the time generating means 7 receives a time interrupt of a fixed period, the time corresponding processing control means 8 checks whether or not there is a process to be executed at that time, and if there is a process to be executed, executes it. . When a time change notification is received from the time change determining means 4 indicating that time overlap has occurred and the internally generated time has been designated, the time corresponding processing suppression control process (step 8-1) is executed, and the time Upon receiving a time change notification designating that a blank has occurred and the external input time and the internally generated time, a time-dependent processing promotion control process (step 8-2) is executed. Further, a process of generating execution history information of the process and recording the information in the execution history information storage unit 9 is also performed. Details of each of these processes will be described later.

On the other hand, when the time change determination means 4 notifies the time change determining means 4 that the time difference of the time difference has occurred and the external input time and the internally generated time, the time change history information generating means 5 determines that there is a time overlap. History information recording processing (step 5-
When 1) is executed, and when the fact that the time gap of the time difference has occurred and the external input time and the internally generated time are notified, the history information recording processing with the time gap (step 5-2) is executed.

FIG. 3 shows a configuration example of the time change history information storage means 6. The time change history information storage means 6 is composed of a semiconductor memory, a magnetic disk device, or the like. The time change history information generation means 5 secures two time change history information storage areas 6-1 on the time change history information storage means 6 each time there is a notification from the time change determination means 4, and stores Record the following information:

When it is notified that a time gap of the time difference X has occurred and the external input time Y and the internally generated time Z are notified, the time information storage area 6-1 of one time change history information storage area 6-1. 1 and the “time zone end” in its time change status storage area 6-1-2, and the time information storage area 6-1 of another time change history information storage area 6-1. −
1, the external generation time Y and the time change status storage area 6-1.
In “−2”, “time zone start” and “there is a blank between X” are recorded. For example, if there is a time correction to advance to 13:45:00 when the time generation unit 7 indicates 13:30:00, the time difference X is +15 minutes, and the external input time Y
Is 13:45:00 and the internally generated time Z is 13:30:00, and information as shown in FIG. 4 is recorded.

When it is notified that time overlap of time difference X has occurred, and that external input time Y and internally generated time Z have been notified, time information storage area 6-1 of one time change history information storage area 6-1. 1 and the “time zone end” in its time change status storage area 6-1-2, and the time information storage area 6-1 of another time change history information storage area 6-1. −
1, the external generation time Y and the time change status storage area 6-1.
In "-2", "time zone start" and "X overlap" are recorded. For example, if the time generation unit 7 indicates that the time is 13:30, the time is delayed until 13:15:00, and the time difference X is -15 minutes, and the external input time Y is 13:15. Minute 00 seconds, internally generated time Z is 13:30
The minutes are 00 seconds, and information as shown in FIG. 5 is recorded.

FIG. 6 is a block diagram showing a configuration example of the time corresponding processing control means 8. The time corresponding processing control means 8 in this example includes a control unit 81 and a processing unit 82-1 for each time corresponding processing.
82-n, an execution history information generation unit 83, a time table 84, and an overlap processing control table 85.

The time table 84 stores, for each time-corresponding process, information on a time zone to be executed and an executed flag for managing whether or not the execution has been completed. The executed flag is set to “1” when the process is executed, and is reset to “0” at a predetermined time, for example, 0:00:00 AM.

When the time change judging means 4 notifies that the time overlap has occurred and the internal generation time, the overlap processing control table 85 stores the control information for the subsequent suppression control processing of the time correspondence processing. It is a table to keep.
The overlap processing control table 85 is stored in the time change determination unit 4.
"1" when notified that time overlap has occurred
And the duplication flag reset at the end of the suppression control processing of the time corresponding processing and the internally generated time notified from the time change determination means 4 are stored as the pre-correction time.

The processing units 82-1 to 82-n are responsible for time corresponding processing, and execute predetermined time corresponding processing when activated by the control unit 81. As a specific example of the time correspondence processing, when the device 10 with a clock function is a service device such as a cash dispenser that changes the charge to the user for each time zone, the charge information is internally changed. Processing. When the device 10 with a clock function is a device that automatically performs a wake-up call to customers, for example, there is a process of automatically calling each customer and sending a message. Of course, application to various other processes is possible.

The execution history information generating unit 83 includes a processing unit 82-
This is means for generating execution history information 1 to 82-n and storing it in the execution history information storage means 9. FIG. 7 shows a configuration example of the execution history information storage means 9. The execution history information storage means 9 is composed of a semiconductor memory, a magnetic disk device, or the like. The execution history information generating means 83 is provided from the control unit 81 to a certain processing unit 8.
2-i (i = 1 to n) is activated, and when the activation time is received, one execution history information storage area 9-1 is secured on the execution history information storage means 9 and the processing information storage area 9-1
-1 is stored in the execution time storage area 9-1-2. For example, when a processing unit called process A is activated at time 18:00:10 seconds,
Information as shown in FIG. 8 is recorded.

The control section 81 is a means for controlling start-up of time-dependent processing by time interruption generated at a fixed period from the time generating means 7, and control of suppression and promotion of time-dependent processing. FIG. 9 shows an example of processing performed by the control unit 81 when a time change notification is received from the time change determination unit 4 in FIG.
An example of a process performed by the control unit 81 when a time interrupt is issued from the time generation unit 7 at 0 is shown.

The operation of the time corresponding processing control means 8 will be described below with reference to the drawings.

Upon receiving the time change notification from the time change determining means 4, the control section 81 starts the processing shown in FIG. First, the content of the time change notification is determined (step S
1) If the time overlap occurs, the processing of step S2 is performed, and if the time gap occurs, the processing of steps S3 to S10 is performed.

If time overlap has occurred, in step S 2, the internal generation time notified by the time change determination means 4 (the generation time of the time generation means 7 immediately before correction) is set before the correction in the overlap processing control table 85. The time is set and the duplication flag is set to "1". The process of the control unit 81 at the time of receiving the notification that the time overlap has occurred is only this step S2. When the overlap flag is set to "1", the time interrupt described with reference to FIG. At times, the suppression control of the time corresponding processing is performed.

On the other hand, if a time gap occurs, the internal generation time (the generation time of the time generation unit 7 immediately before correction) notified from the time change determination unit 4 changes to the external input time (correction of the time generation unit 7). The blank time zone up to the specified time is internally stored (step S3), and the promotion control of the time corresponding process in steps S4 to S10 is performed as follows.

Attention is paid to the first process in the time table 84 (step S4), and it is checked whether or not the execution time period overlaps with the blank time period (step S5). It is checked whether it is "0" (step S6). If the execution time period does not overlap with the blank time period, or if the execution time flag is "1" indicating that execution has been completed even if it overlaps, attention is shifted to the next process in the time table 84 (step S9). If the execution time period overlaps with the blank time period and the executed flag is “0” indicating no execution, the processing unit 82-i in charge of the process is activated (step S <b> 7). Then, the execution flag is set to "1", and at the same time, the name of the started process and the start time are notified to the execution history information generating unit 83 to record the execution history information (step S8). Attention is shifted to the next process in the middle (step S9). Note that the time notified at the previous time interruption may be used as the start time, or a new time may be obtained from the time generation means 7.

When the control section 81 repeats the processing of steps S5 to S8 until the last processing registered in the time table 84 (YES in step S10), the control for promoting the time corresponding processing ends. As a result, the processes to be started during the blank time period can be started promptly without omission.

Further, when there is a time interrupt from the time generating means 7, the control section 81 starts the processing shown in FIG. First, it is determined whether or not the duplication flag of the duplication processing control table 85 is "1" (step S11). If it is "0", it is not necessary to execute the time-dependent processing suppression control. Normal processing is performed, and if the duplication flag is 1, control for suppressing the time corresponding processing in steps S19 and S20 is performed.

In the normal processing, attention is paid to the first processing in the time table 84 (step S12), and it is checked whether or not the internally generated time notified this time by the interruption is included in the execution time zone of the processing (step S13). , If included, the executed flag of the process indicates “1” indicating that the process has been executed.
It is checked whether it is (Step S14). If the internally generated time is not included in the execution time slot, or if the executed flag is "1" even if it is included, the process is shifted to the next process in the time table 84 (step S17). If the internally generated time is included in the execution time zone and the executed flag is “0” indicating that the processing has not been executed, the processing unit 82-i responsible for the process is activated (step S <b> 15). Then, the execution flag is set to "1", and at the same time, the execution process name and the activation time are notified to the execution history information generation unit 83 to record the execution history information (step S16). Attention is shifted to the next processing in the middle (step S17).
When the control unit 81 repeats the processing of steps S13 to S16 until the last processing registered in the time table 84 (YES in step S18), the processing relating to the current time interruption ends. Thus, the process to be started at the internal generation time can be started without omission.

On the other hand, in the suppression control of the time corresponding processing performed when the duplication flag is “1”, the internal generation time notified by the current interrupt has reached the pre-correction time recorded in the duplication processing control table 85. It is determined whether or not it has not yet reached (Step S19). If it has not yet reached, it is still the overlapping time, so Steps S12 to S as performed in the normal processing are performed.
Step 18 is not executed, and the process related to the time interruption ends. Conversely, if the internally generated time notified by the current interrupt has reached the pre-correction time recorded in the overlap processing control table 85 (NO in step S19), the overlap time period has passed and the overlap processing control table After resetting the duplication flag of No. 85 to “0” (step S20),
The process proceeds to step S12 to perform the above-described normal processing. By such control, double starting is prevented without performing unnecessary processing.

In the above embodiment, the hour, minute, and second are used as the time information. However, the present invention can be applied to a case where the time is indicated only by the hour and minute. The present invention is also applicable to a device that handles a time including the time up to.

[0044]

As described above, according to the present invention, the following effects can be obtained.

When the time of the time generating means is corrected based on a time provided from outside, the time is linked to the time based on the time indicated by the time generating means at the time of time correction and the time at which the time was corrected. In order to control the promotion or suppression of the execution of the processing to be performed, even if the internally generated time becomes discontinuous due to time correction, the time corresponding processing will not be executed or will not be executed twice, The time can be adjusted immediately.

Since the time change history information is recorded in the time change history information storage means, it is possible to investigate what time correction has been performed in the past. For this reason,
When the execution time of the time corresponding process becomes abnormal, it is possible to confirm whether or not the cause is due to an incorrect time correction.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a flowchart showing an outline of processing of the device with a clock function.

FIG. 3 is a diagram showing a configuration example of a time change history information storage unit.

FIG. 4 is a diagram showing an example of time change history information recorded in time change history information storage means when a time gap occurs due to time correction.

FIG. 5 is a diagram showing an example of time change history information recorded in time change history information storage means when time overlap occurs due to time correction.

FIG. 6 is a block diagram illustrating a configuration example of a time corresponding processing control unit.

FIG. 7 is a diagram illustrating a configuration example of an execution history information storage unit.

FIG. 8 is a diagram illustrating an example of execution history information stored in an execution history information storage unit.

FIG. 9 is a flowchart illustrating an example of a process performed by a control unit of a time corresponding process control unit when a time change notification is received from a time change determination unit.

FIG. 10 is a flowchart illustrating an example of a process performed by a control unit of a time corresponding process control unit when a time interrupt is issued from a time generation unit;

FIG. 11 is an explanatory diagram of time blanks and time overlaps that occur when the time of the time generating means is immediately changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... External time input means 2 ... Time difference calculation means 3 ... Time change means 4 ... Time change determination means 5 ... Time change history information generation means 6 ... Time change history information storage means 7 ... Time generation means 8 ... Time correspondence processing control Means 9 ... Execution history information storage means 10 ... Device with clock function 11 ... Input device 12 ... Display device 13 ... Recording medium 81 ... Control unit 82-1 to 82-n ... Processing unit 83 ... Execution history information generation unit 84 ... Time Table 85: Duplication processing control table

Claims (5)

[Claims] 1. An apparatus having a clock function for performing processing based on the time indicated by the time generating means in the apparatus, wherein the time of the time generating means is determined based on a time given from outside. When the time is corrected, based on the time indicated by the time generating means immediately before the time correction and the time at which the time is corrected, the promotion of the execution of the process linked to the time or the suppression of the execution is controlled. A time change support method, characterized in that: 2. An apparatus having a clock function for performing processing based on the time indicated by the time generating means in the apparatus, wherein the time of the time generating means is controlled based on a time given from outside. A time changing step of correcting the time, and when the time of the time generating means is advanced by the time changing step, the time is adjusted from a time indicated by the time generating means immediately before the time is corrected to a time corrected by the time changing step. When the time of the time generating means is delayed by the time changing step, the time indicated by the time generating means immediately before the time correction from the time corrected by the time changing step. And a step of suppressing execution of processing to be performed by the time. 3. An apparatus having a clock function for performing processing based on a time indicated by the time generating means in the apparatus, wherein the time of the time generating means is determined based on a time given from outside. A time changing means for correcting the time, when the time of the time generating means is advanced by the time changing means, from the time indicated by the time generating means immediately before time correction to the time corrected by the time changing means If the time generation means is to be executed quickly and the time of the time generation means is delayed by the time change means, the time from the time corrected by the time change means to the time indicated by the time generation means immediately before the time correction A time change support device, comprising: a time corresponding process control unit that suppresses execution of a process to be performed. 4. An apparatus having a clock function for performing processing based on an internally generated time of the time generating means, wherein the external time input means inputs a time from outside the apparatus. Time changing means for correcting the internally generated time indicated by the time generating means to the external input time input at the external time input means, and externally input time input from outside at the external time input means and internally generated at the time generating means. Time difference calculating means for calculating a difference from the internally generated time; analyzing the time difference calculated by the time difference calculating means;
Time change determining means for determining how much the internally generated time has been advanced or delayed, and time correspondence for controlling the suppression or promotion of the execution of the processing linked to the time based on the determination result of the time change determining means. Processing control means; time change history information generation means for generating time change history information including information on the determination result of the time change determination means, information on the internally generated time, and information on the external input time; A time change support device comprising: time change history information storage means for storing time change history information generated by history information generation means. 5. A computer system having a clock device in a computer system and performing processing based on the time indicated by the clock device, wherein a computer controls the time of the clock device based on a time given from outside. A time changing step to be corrected; and, if the time of the clock device is advanced by the time changing step, a process to be performed from a time indicated by the clock device immediately before time correction to a time corrected by the time changing step. A step of promptly executing, and, when the time of the clock device is delayed by the time changing step, a process to be performed from a time corrected by the time changing step to a time indicated by the clock device immediately before the time correction. And a machine-readable record of a program for executing the steps of: Media.