SYMPTOM:
The trigger time of a schedule appears shifted by a few minutes from the originally value when editing a schedule object in Strategy Developer. Consider the screenshot below in which the time to trigger is shown as '12:59:00 AM' even when the it was set to '01:00:00 AM' when the schedule was originally created.

CAUSE:
This issue can be observed when there is a difference in the system time between the Intelligence Server and the Developer machine.
ACTION:
Make sure that the system time in the client machine where Developer is installed matches the time in the Intelligence Server machine.