I am publishing to my Zimbra calendar from Mozilla Sunbird, and I noticed a funny thing: when I schedule an event that does not start on a 30 minute boundary (e.g: starts at 10:15am), the publish works: the event shows up in my Zimbra calendar, but when another user tries to use Schedule to access my Free/Busy information, the block does not show me as busy in his Schedule view. I verified this by creating two events with exactly similar details except the first starts at 10:15am and the second at 12:00 noon. Only the latter shows up in the Schedule view.

There must be a setting, I am guessing, that specifies time slots/intervals and perhaps my current settings only permit 30 minutes? Unfortunately, I am not able to find such a setting.

Anyone else noticed this?