Chronorder is a file renaming program.

Its default behavior is to sort the files in the current 
directory in ascending chronological order (oldest first).
Every file gets an index number prepended to it. This 
assures that the alphabetical order of the files matches
the chronological order.

A use case for the program is for example a directory 
containing pictures of some event taken by different cameras.
The alphabetical order of the pictures can then be matched
with the chronological order using this program.

Keep in mind that this program alters the actual file names
on disk. After confirming the safety question there is no
automatic way to undo the changes, only manually.