Stays typically credit to the year of the check-in date. If you want a stay to count for next year, you'll have to check-in next year. Be careful to leave a day between stays if you're checking in/out of the same hotel (in 1st/out2nd; in 2nd/out3rd =1stay ~ in 1st/out 2nd; in 3rd/out4th = 2 stays ).