shellutils; No way to input a date in time_t format

[Roland Mas]

Package: shellutils
Version: 2.0.11-1
Severity: wishlist

As a programmer, I often encounter dates in the time_t format
(e.g. 983370715), and I'd like the 'date' command to understand them
and to display them in a more readable way.  Unfortunately, GNU date
seems to provide no way (no documented way, at least) to use that
format as input.

Someone suggested a trick to me, but I guess you'll agree it's ugly:
$ date -d 'Jan 1 1970 00:00:983370715 GMT'

So, I hereby express a wish for a new input format for 'date'.

-- System Information
Debian Release: testing/unstable
Kernel Version: Linux cachemir 2.4.0 #1 Thu Jan 25 14:01:26 CET 2001 i686 
unknown

Versions of the packages shellutils depends on:
ii  libc6          2.2.2-1        GNU C Library: Shared libraries and Timezone
ii  login          20000902-2     System login tools
hurd    Not installed or no info