Pretty handy project. I think probably most of us have to look this stuff up from time to time when parsing timestamps. Nice work.
Actually after we started working on it, we found five projects, attempting to solve the same problem: foragoodstrftime.com, strftime.org, strftime.net, strftimer.com, strfti.me
None of them were ideal though. We analysed them, took the best parts, threw away the worst - this is how strftime.guru appeared.