I would say that it also depends on where you want to practice. There are certainly many hospitalist oportunities in small cities/towns that are desperately looking to recruit new graduates. If you plan to work in a big city (e.g. NYC, Chicago) you might want to start a bit earlier so that you get first pick on the good offers from the well known programs. I started looking november, lined up several interviews between december-january and got an offer in January. I have to say that many programs in big cities do not advertise and you may have to do a lot of calling, emailing, sending letters to HR to put yourself out there. It's a little harder if you are applying to jobs in a big city coming from a different place because you don't necessarily have the inside scoop.
If you want to have more control of the type of job/place where you want to work, then I would start earlier (November) so you can get something that is more consistent with what you want. If you don't care much where you want to work, you can definitely start much later and get whatever is available at that time. Also, keep in mind that all the stuff with licensing, credentialing, hospital priviledges takes time and you want to give yourself plenty of room to have all those things completed by July if you intend to start practicing then.
Many of my colleagues that got jobs at major university programs landed their positions by late January.
Good Luck!!