Here are several examples:
You are probably more interested in this flavor....
The find command is really powerful as you can search for files modifed down to an exact (well almost) time using a reference file
touch -t 03201600 /tmp/datefile
creates a file with timestamp of March 20, 4:00
find . -newer /tmp/datefile -print
find files newer than timestamp of datefile - granular to within one minute