In any file manager type program (I use Xplorer2, which you can get
free from
http://www.zabkat.com/x2lite.htm vastly superior to Windows
File Manager). You can sort files by date and time simply by clicking
on the Date Modified column. The night time files will be
consecutively listed by time. Highlight the first you don't want, hold
down shift, select the last night file and hit DEL.
David