Definitely check out the NaNo Sponsors page. You can often try new software for free. You might find Plottr useful. I think that's the one that allows you to create different timelines. I didn't check to see if they are sponsoring this year, but they often are. I got it and like it and when I get back home from my trip, I plan to try to use it again for this novel.

If you 'win' NaNo, you can get most of the softwares for a discount.