Didn't even cross my mind to post it on the application's blog!
Thanks for your comments. It's been such a push to launch that I can now start focusing on tweaking the product; internationalisation etc.
Edge cases are a pain. I'm having some discussions with a potential client at the moment and the challenge is turning development for the edge cases that they would like into something that can be extended to all users.
It currently deals with what I think are federal holidays in the US but won't automatically handle state-level holidays. So, if somebody in the US books 5 days crossing 4 July, it won't count 4 July so they'd only use 4 days from their allowance.