Subsetting (thinning) Files

I use the free version of TimeSnapper to help with reporting hours worked on various projects. The program saves a screen capture (png) at a user specified capture rate. To keep the logs manageable I have set the capture rate at one capture every 5 minutes.

Recently the program reset itself to its default of one capture every 5 seconds. I now have several days of log files that I would like to thin down to one capture every 5 minutes, because the capture files are taking up too much space and I have to browse through too many files to find what I want.

Does anyone know of a way to thin these files down, leaving me with only one capture every 5 minutes. To complicate issues, TimeSnapper stops capturing when the computer is not in use (as when I'm in a meeting or at lunch), so it's not quite as simple as keeping every 60th file and deleting the rest.

Thanks.

 

Using Win XP SP3. Not using CCleaner though I was trying out UnHackMe.

I have TimeSnapper set to 300 seconds, but a few days it reset itself to the default of 5 seconds. This happened to me before, possibly when I ran a registry defrag; I don't really remember. At the time I caught it pretty quickly so I didn't have to delete too many files.

This time I have a few days work of captures to thin down from over 4000/day to about 100. any thoughts on a program or Windows batch script that could do it for me based on timestamps?