I've been sitting on this for a while, but I finally cleaned up the simple utility I was using to split apart my combat log files after a week or so of raiding to the point where I feel comfortable sharing it.
Once upon a time I used to wait a few seconds loading log files into wordpad (the only text editor handy that can handle it) and search by date for where the break the file. Then since the log from a raid is still too large for the clipboard I had to delete the parts I didn't want and save to a different file (careful not to overwrite the original combat log file). Then repeat over and over for as many logs as I needed to split out.
I did that for a few weeks before deciding it would be easier to write a program to do that and some of the other repetitive tasks I was doing like naming the files by raid name and date. So I wrote a quick program to parse the file, find the breaks and write out smaller logs. A little speed tweaking later and there is sat for a few more weeks. Usable, but not quite there.
So now I've got the finishing touches on it where you can set up how long to wait before splitting to a new log file (minimum time between raids), name output files automatically by raid name if one was configured, directory to look for combat logs, directory to save into, etc.
Without further ado, download it here and try it out for yourself. I repurposed a website I had made a couple years ago and just ripped out the old content so it's pretty sparse, but it works. If you have any feedback feel free to comment. I draw the line at automatically uploading stats to various website (there are too many and they change too often), but anything short of that is fair game.