Do this now: register for end-of-year Hilton and Marriott 2015 promotions

Registration has opened for what I assume are the final global promotions of 2015 for Hilton HHonors and Marriott Rewards.

Hilton HHonors Triple your Trip

Between September 1 and December 31, 2015, earn double base HHonors points Monday through Thursday nights and triple base HHonors points and Friday, Saturday, and Sunday nights. Register for the promotion here.

I found after my overnight stay last Sunday at a Hilton property courtesy of Delta that I earned base points on charges I made to my room, which triggered the current Double Your HHonors promotion and my Diamond elite bonus. Just one more reason why, even if you don't have any paid stays coming up, you should register now, before you forget.

Marriott Rewards MegaBonus

Between September 15, 2015, and January 15, 2016, earn double base points on each paid stay, starting with your second paid stay. Register for the promotion here by November 15, 2015. Ritz-Carlton properties are not participating in this promotion.

Since Marriott Rewards is the second-least rewarding program for paid stays, it's hugely unlikely that this promotion will make it worth directing paid stays to Marriott. But it doesn't cost anything to register now, before you forget.