I have a track group called "Jingles" (actually two, a short jingle and long one).
They are 5 seconds on average for the short one and 10 for the long ones.
When scheduling that track group in the clock, for the "play time" it schedules 10:00 for the long ones and 5:00 for the short ones. Basically it's thinking the seconds is minutes and milliseconds is seconds.
It's fine in Playit live when not using the manager, this only happens when in manager mode.
As an update, this only happens when the short group is the first item on the list. When it's further down it works fine.
It came about trying to schedule a short jingle at the top of the hour