We use Outlook Calendar to schedule our training rooms and computer labs. When scheduling the labs, for instance, we will schedule a training session for a certain date from 8:00 am to 10:30 am.  Prior to the event occurring, the calendar shows the correct times, however when the event occurs, the calendar changes the event to show 8:00 am to 8:10 am.  This only occurs on the lab calendars and not any of the others training calendars.

Ideas?

Does it happen when you book the schedule time of computer labs?

Please log onto the account of source mailbox through Outlook or OWA and direct book it to check if the issue still persists.

If the lab's mailbox is corrupted, please move it to another data store in Exchange site.

Thanks.

Tony Chen
TechNet Community Support