Currently an issued trigger is atomic - it is one thing which lasts for as long as you care to configure it.
However, if a trigger is longer than a millislice, GT should break the trigger up into the appropriate number of millislice-sized subtriggers, packing an extra word into the trigger header with the trigger number of the first trigger in this sequence. This makes the event builder's job waaaaay easier.
#1 Updated by Alec Habig about 8 years ago
Have this working, created a GTLongTrigs class which calculates the need for splitting a trigger into smaller chunks, and provides the functionality to loop over that series of smaller triggers, adjusting the time windows appropriately.
Have it working in a test release, doing more testing and looking for a way to clean up the resulting code before releasing it on the world.