According to Gilles Detillieux:

Cool. I had to do this just last week. After wasting half an hour digging through man pages and Google searches, I gave up and wrote a q&d C program. It seems there ought to be a way to do this with "date -d", but I can't find a way to get it to take seconds since epoch as an input.

Not sure it can be done with the "date" command.

For that matter, I can't figure out how to get it to output the date as such either.

According to the date(1) man page under Red Hat Linux (any version): %s seconds since 00:00:00, Jan 1, 1970 (a GNU extension) So, as long as you have the GNU "date" command, "date +%s" ought to do what you want there.

According to Sean A. Walberg:

...

Been trying to do this one for ages... Best I can come up with uses a perl one liner:

perl -e 'print scalar localtime 1102434671'

I've been using a small perl script called "ctime" (attached) for years now. It's not a one-liner, like the above, but it does simple argument handling, calling the perl ctime() function for each numeric argument (or for the current time in the case of no arguments). It also accepts hex strings in addition to decimal numbers as arguements, and converts them as required. The following shows the (slight) difference in output format between the GNU date command and the perl ctime script, and also shows that `date +%s` does provide a compatible numeric date format... % date ; ctime `date +%s` Tue Dec 7 11:35:08 CST 2004 Tue Dec 7 11:35:08 2004 % -- Gilbert E. Detillieux E-mail: <gedetil@cs.umanitoba.ca> Dept. of Computer Science Web: http://www.cs.umanitoba.ca/~gedetil/ University of Manitoba Phone: (204)474-8161 Winnipeg, MB, CANADA R3T 2N2 Fax: (204)474-7609