I have only once managed to get a Campaign to go at a scheduled time and to sure what I did differently.
Campaigns are active, and date selected from Calendar (just in case US format issues). Did the same with time as well.
As a user, my Time Zone is correct GMT +10 (Tools, Preferernces, Date and Time). I am sending on behalf of another use and his time Zone is correct too.
When I create a task or history - date and time stamp is as expected so I am confident that ACT knows our time Zone.
AMA seems to not know the Time Zone.
When in a Campaign and I click the arrow to select time, the default time zone is GMT -5.00 and right now the pre-populated date is 8 March (it's really 9 March) and the prepopulated time is 11.43 PM, it's really 10.45 AM.
I think this is where the problem lies.
Obviously, I change the time zone when scheduling but that's not helping.
Other points to note - we send from our own domain