Homepage: https://www.gnu.org/software/emacs
Maintain last change time stamps in files edited by Emacs
A template in a file can be updated with a new time stamp when
you save the file. For example:
static char *ts = "sdmain.c Time-stamp: <2020-04-18 14:10:21 gildea>";
To use time-stamping, add this line to your init file:
(add-hook 'before-save-hook 'time-stamp)
Now any time-stamp templates in your files will be updated automatically.
See the documentation for the functions `time-stamp'
and `time-stamp-toggle-active' for details.