Can you please tell how the times work when waiting for gifts to open?

The odds of receiving a Marvelous prize from a pink star box is 1 in 10. So you'll need to open around 10 pink star boxes, sometimes more, sometimes less to get one of the two prizes. The prize you receive is based on the current seasonal set, even if you earned the box prior. So to increase your chances next month, save pink star boxes (do not open them) until then.