Knowledgebase: Google
Events created before lookback on the device have different behavior
Posted by Account Management Team on 28 October 2009 03:56 PM
Google:

Information: The behavior for events that are created on the device before the lookback date (IT Policies -> Calendar Sync Settings) differs depending on whether the events are recurring or not. Recurring events that have all their instances prior to the lookback will be removed from the device after the next PIM cycle. However, standalone events that are created prior to the lookback on the device will not be removed from the device on the next cycle.