Replication schedules and daylight savings time

Daylight Savings Time affects replication schedules that are triggered according to a time period, such as every hour, every thirty minutes, and so on. Replication schedules that are triggered at a fixed time that you specify are not affected.

In the following examples, the time change occurs at 2:00 a.m.

In this example, the summary period is configured to be every 30 minutes. On the "fall back" day, will be two extra summaries performed during the repeated hour for that day. For the "spring forward" day, there will be two summaries missing because of the skipped hour. The next replication occurs at the next scheduled time. In this case, it would be 3:00 a.m.

In the next example, the summary period is configured for every four hours. The scheduled summaries do not occur exactly on or within the boundaries of the time change hour. In this case, on the "fall back" day, the summary subsequent to the time change hour includes four hours of data for the "fall back" day. An extra summary for an hour’s worth of data is performed at the end of the "fall back" day. On the "spring forward" day, the summary period that contains the skipped hour includes one less hour of data.

For a custom summary period, the summaries always occur at the fixed times of day that you specify in local time. However, the summary includes and extra hour of data for the "fall back" day (because of the overlap hour) and for the "spring forward" day (because of the skipped hour).

If a Daylight Savings Time change causes a scheduled time to be ambiguous, such as 1:30 a.m. on a "fall back" day when the clock jumps from 1:59 a.m. Daylight Savings Time to 1:00 a.m. standard time and the time could be interpreted as 1:30 a.m. Daylight Savings Time or 1:30 a.m. Standard Time, the replication will occur at the latter of the two occurrences. In this case it would be 1:30 a.m. Standard Time.