JavaScript optimization challenge

Hi, we're hosting the JS optimization challenge right now, with cash prizes and all. Link to full rules.

The challenge: make JS strftime function very fast, and beat the performance of GNU libc's strftime.

The slower code that can be used as a base for optimizations is here: github.com/mvasilkov/strftime
You're free to use that source as the base of your solution.

To make things interesting, we're not providing the reference benchmark. The benchmark will run on V8 (Node.js) engine.

Send your solutions to (as attachments, GitHub gists or whatever). Last date for submission is June 22, 2014. Winners will be announced on June 29.