Scenarios
Each row in the following table is based on a time-initiated EXEC named BACKUP that has specified
- A start time when the EXEC should run
Either an end time when the EXEC should stop running or stop count (which specifies how many times the EXEC runs)
- An interval (20 minutes)
Daylight saving time examples
Scenario | If a time-initiated EXEC is scheduled to run | Column 1: Changing the MVS system clock forward from 2:05 A.M. to 3:05 A.M., the EXEC | Column 2: Changing the MVS system clock backward from 2:05 A.M. to 1:05 A.M., the EXEC |
|---|---|---|---|
A | Start time = 1:00 A.M. End time = 1:40 A.M. The EXEC should execute 3 times from 1:00 A.M. to 1:40 A.M. | Executes normally at
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT. | Executes a complete cycle at 1:00 A.M. PDT and a partial cycle after 1:05 A.M. PST, executing for a total of 5 times:
At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST and the EXEC begins executing again at
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B | Start time = 1:00 A.M. End time = 2:20 A.M. The EXEC should execute 5 times from 1:00 A.M. to 2:20 A.M. | Executes a partial cycle at 1:00 A.M. and stops earlier than expected at 2:05 PST, executing only 4 times:
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute for the last time at 2:20 | Executes a partial cycle at 1:00 A.M. PDT and a partial cycle at 1:00 A.M. PST, executing for a total of 8 times:
At 2:05 PDT, the time changes backwards to 1:05 A.M. PST so the EXEC does not execute for the last time at 2:20. The EXEC starts executing again at
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C | Start time = 1:00 A.M. Count = 5 Note that BMC AMI OpsA internally calculates that count = 5 is equivalent to specifying a stop time ending at 2:20 A.M. | Executes a partial cycle at 1:00 A.M. and stops earlier than expected at 2:05 PST, executing only 4 times:
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute for the last time at 2:20 | Executes a partial cycle at 1:00 A.M. PDT and a partial cycle at 1:00 A.M. PST, executing for a total of 8 times:
At 2:05 PDT, the time changes backwards to 1:05 A.M. PST so the EXEC does not execute for the last time at 2:20. The EXEC starts executing again at
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Example for row C, column 1 EXEC: runs1 runs2 runs3 runs4 clock changes does not run PST 1:00am 1:20am 1:40am 2:00am 2:05am -------+-------+-------+-------+-------+-------+------+----- PDT 3:05am 3:10am 3:30am | |||
Example for row C, column 2 EXEC: runs1 runs2 runs3 runs4 clock runs5 runs6 runs7 runs8 changes PST 1:05am 1:20am 1:40am 2:00am 2:20am -------+------+------+------+------+------+------+------+------+--- PDT 1:00am 1:20am 1:40am 2:00am 2:05am | |||
D | Start time = 1:30 A.M. End time = 1:50 A.M. The EXEC should execute 2 times starting at 1:30 A.M. | Executes normally at
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT. | Executes through 2 complete cycles beginning at 1:30 A.M. PDT and again at 1:30 A.M. PST, executing for a total of 4 times:
At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST and the EXEC begins executing again at
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E | Start time = 1:30 A.M. End time = 2:30 A.M. The EXEC should execute 4 times starting at 1:30 A.M. | Executes a partial cycle at 1:30 A.M. and stops earlier than expected, executing only 2 times:
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute for the last 2 times at 2:10 A.M. PST and 2:30 A.M. PST. | Executes a partial cycle at 1:30 A.M. PDT and executes a complete cycle at 1:30 A.M. PST, executing for a total of 6 times:
At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST and the EXEC begins executing again at
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F | Start time = 1:30 A.M. End time = 3:30 A.M. The EXEC should execute 7 times starting at 1:30 A.M. | Executes a partial cycle at 1:30 A.M. and stops earlier than expected, executing only 4 times:
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute at 2:10, 2:30, and 2:50 A.M. PST but continues at
| Executes a partial cycle at 1:30 A.M. PDT and executes a complete cycle at 1:30 A.M. PST, executing for a total of 9 times:
At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST and the EXEC begins executing again at
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G | Start time = 1:30 A.M. Count=5 | Executes a partial cycle at 1:30 A.M. and stops earlier than expected, executing only 2 times:
At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute for the last 3 times at 2:10, 2:30 and 2:50. | Executes a partial cycle at 1:30 A.M. PDT and executes a complete cycle at 1:30 A.M. PST, executing for a total of 7 times:
At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST and the EXEC begins executing again at
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Example for row G, column 1 EXEC: runs1 runs2 clock changes PST 1:30am 1:50am 2:00am 2:05am -------+-------+-------+-------+-------+-------+------+----- PDT 3:05am 3:10am 3:30am 3:50 The EXEC runs for a total of 2 times. | |||
H | Start time = 2:30 A.M. End time = 2:50 A.M. The EXEC should execute 2 times starting at 2:30 A.M. | Does not execute at all as the clock time is changed At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute at 2:30 or 2:50. | Executes through 1 complete cycle but the cycle begins 3.5 hours after midnight instead of 2.5 hours after midnight At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST so the EXEC does not run at 2:30 PDT but when the time becomes 2:30 A.M. PST, the EXEC begins executing at
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I | Start time = 2:30 A.M. End time = 3:50 A.M. The EXEC should execute 5 times starting at 2:30 A.M. | Executes a partial cycle executing 3 times starting at 3:10 A.M. PDT At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute at 2:30, 2:50 A.M. and starts to run at
| Executes through 1 complete cycle but the cycle begins 3.5 hours after midnight instead of 2.5 hours after midnight At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST so the EXEC does not run at 2:30 PDT but when the time becomes 2:30 A.M. PST, the EXEC begins executing at
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J | Start time = 2:30 A.M. Count = 2 | Does not execute at all as the clock time is changed: At 2:05 A.M. PST, the time changes to 3:05 A.M. PDT so the EXEC does not execute at 2:30 and 2:50 A.M. in the morning. | Executes through 1 complete cycle but the cycle begins 3.5 hours after midnight instead of 2.5 hours after midnight At 2:05 A.M. PDT, the time changes backward to 1:05 A.M. PST so the EXEC does not run at 2:30 but when the time becomes 2:30 A.M. PST, the EXEC begins executing at
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