How to delete a gap in an After Effects timeline ...without having to carefully select everything after the gap, and shift it all up.

All articles/videos I see only talk about  trimming the timeline at the beginning or end, but I can't find anything about cutting out a piece in the middle. 

Basically, I want the inverse of Trim Comp to Work Area. I want to remove a piece of the full comp in the middle of the timeline.

Is that possible?
There's a script that does it for you (I just wrote it). You can get it (free, open source, WTFPL license) here on my blog. With the playhead in a gap, run the script and it will pull the layers after the gap along so the gap disappears. 

BTW all care, no responsibility. It works on my machine, but I've tested it like, twice. Save before using.