Multiple of the recent RFCs closed their voting later than the announced
date and some of the closer ones were lacking a clear end time as well.
As while ago I've stumbled upon the fact the the voting doodle supports
automated closing using using the "closeon" attribute which takes a
string that is passed to 'strtotime()'.
Tests show that this attribute actually works properly:
I've added this to the example doodle in the RFC howto wiki page: