My user\backup folder contains over 266,000 files, all pertaining to two calc files I open once daily. The backup files are continuing to be created whether those two calc files are open or not, at a rate of over 700/day!!
Why is this happening?
Why is it dark over night ??
Youre the guy in front of your keyboard!
The files are likely recovery information, rather than backup files. You probably have the interval for this setting at something like 2 minutes. Related help page here.
This seems to be a bug they already fixed. https://bugs.documentfoundation.org/show_bug.cgi?id=71625. Update your LO to the latest one.