After a cursory Super Search for obfus with "clock" or "time" or "tick" or "tock" in the title, What time is it?, found by tye above, looks the closest fit to your description that I could see.

If you're interested in other time-based obfus, you might enjoy:

• Camel Time
• Clock
• Tick-tock
• Tick-tock 2, a self-modifying quine
• time
• time quine
• This was a lot of fun

If you're interested in historic obfus see:

• The Top Ten Perl Obfus
• The First Ten Perl Obfus

Update: Yay, Schmunzie eventually found it:

• When JAPH retires (v 2.0) by Elliott
• Also When a PERL Hacker Retires was done the day before (this one just prints a fixed clock face, doesn't use localtime).