Missed syncs occur when the system running the ChronoSync scheduler is asleep, the user is logged out, or the system is shutdown/turned off when the designated time for a scheduled sync comes due. In those cases, the action the user has chosen for “Missed Sync Behavior:” will be invoked for the scheduled sync as soon as the system is awoken, or the user logs in.

The Missed Sync options include:

• “Ignore” – Do nothing. Do not attempt to run the missed sync until the next scheduled date and time.
• “Post error to Scheduler Log” – An error message reporting the missed sync will be logged in the Scheduler Log.
• “Run Immediately” – ChronoSync will try to run the missed sync the next time the background scheduler is running.

You should keep in mind that a missed sync is a scheduled sync that was never attempted at its last scheduled time. That is not the same thing as a scheduled sync that is attempted but fails to complete (e.g. one of the targets is not available). Those are considered failed syncs. Failed syncs are managed by setting the Schedule ‘Options’ where you can enable and configure the ‘Retry on errors’ options.

To modify the Missed Sync Behavior, just launch ChronoSync, choose the ChronoSync Menu->Preferences, and switch to the ‘Scheduler’ preference pane.

If your syncs are missed because the mac is asleep, then you can enable the Preference Setting “Wake system to synchronize” on the same ‘Scheduler’ preference pane. Be sure you don’t have a wake password as this will interfere with waking the mac to run a sync.