Adrian wrote:

That is the same with us, except when the event reminder is set to
None.

You can't set the reminder time to "None". You can only disable the
reminder or set it to a value (zero or higher) if enabled. There is no
"none" choice. If the default reminder is enabled, no matter what time you
choose (even zero), all-day events will have an 18 hour reminder.
--
Brian Tillman [MVP-Outlook]