touch manual file:
-B, --backward=SECONDS
Modify  the  time by  going back SECONDS seconds.  For example,
touch -r foo -B 5 bar will make the file bar  5   seconds   older than file foo.
Never had to fix a mess like that, but touch might work if it's unix/linux based.   I think a day is 86,400 seconds....
I once did a  [  chown -r user:grp .* ] in /home as root   
This has the effect of making all directories owned by one user and group..... oops 

I hate it when my own stupidity makes me work late.