Releasing fixed units

[FroBodine]

I am having a hard time understanding how to release fixed units. I look at the "Releases" command, and it shows a bunch of my units should have released. An asterisk means they missed their release time, according to the manual. A bunch of my units in the list have an asterisk. Why did they miss their release time? They are just sitting there useless to me. I know they will automatically release when you come in contact with them, but how does the "release" schedule work?

Am I supposed to do something to get them to release on their scheduled time?

Thanks!
-=Jeff