I use calc to keep student attendance for each month. I didn’t copy and edit August to create September worksheet, I just started writing over August!?! No backup on my part… am I SOL?
It does (probably) but it might already have been over written.
The path to backups is shown in Tools - Options - LibreOffice - Paths. Copy the .bak file to another location and open from LibreOffice.
It might be worth creating a template and starting each month from the template. Otherwise, look on the extensions site for time stamped save