Within Terminal, `date` command outputs a curious prefix where it should'n

I am using a Mac Mini running Lion (10.7.5) and zsh 4.3.12 (i386-apple-darwin11.0.1) with oh-my-zsh installed. In the Terminal.app I retrieve the UNIX timestamp using the following command

date +%s

It should print out a string of decimal digits - as the time of writing 1357294199, however it prints 27m1357294199. Notice the 27mprefix. It stays constant aka. does not change with time.

I already tried the following but to no avail

• Closed and reopened the Terminal.app
• Restarted my computer

Why does the date command print this extra prefix and how do I get rid of it?

Follow-ups (Note: For the sake of simplicity outputs will use a constant timestamp)

• The command date '+%s' outputs 27m'1357294199
• Command /bin/echo Hello World prints Hello World
• type date gives date is /bin/date
• /bin/date +%s prints 27m'1357294199

The issue was due to a bug in oh-my-zsh:

1. The bug was fixed several months ago: update oh-my-zsh and the issue should be solved.

2. If for any reason you cannot update there is fix on StackOverflow (https://stackoverflow.com/questions/12321564/date-command-with-zsh) but it involves the editing of lib/termsupport.zsh: remove the 12th line (warning I do not have oh-my-zsh installed and cannot check if the line number is really the correct one).