It reminds me a little of early versions of EvE Online, with the offline skill training mechanic. You set a skill training while you were offline, but had to log in to set up another once the existing one had finished - of course, this was before the newfangled queue system that they have now (known as "Skill Tetris"). Since offline training directly affected character progression, players would end up logging in at awful times - from every 5 minutes for low level skills, to the middle of the night for higher level (=longer) skills, just to avoid the terrible feeling of panic that followed the realization that "oh noes I'm not training anything! I'm so behind!"
Here's hoping ZOS doesn't ever decide to follow that model. Every 12 hours is something I can live with. Although I'm tempted to not bother for Provisioning as my Provisioner hireling is still sending my level 40 Provisioner 1 Dripping or 1 Corn Mash. So underwhelming.