I've been using Hg for a while on various machines, but I hadn't noticed anything so regular. I just set up a whole load of machines for some colleagues yesterday with the then-latest version, wondering why downloading the installers seemed so slow. I assume with hindsight that I missed the update by a few hours at most, and maybe the connection was weighed down with release-related tasks.
(Oh, and thanks to the dev team for the hard work, BTW!)