Fogbugz has holidays built into it's "evidence based scheduling", which you can enter for users or sites, as well as working schedules, velocity, etc.
We've been using it for a while, having migrated from Trac, and I'm very happy with it. On Thu, 2010-06-17 at 10:16 +0100, Aaron Trevena wrote: > > Ugh. > > Not sure how that would be any nicer than current spreadsheet I'm > using :( >