leave (something) for another time/day/week/etc.
To reserve or save something for some future point or event. I'm sorry we didn't get a chance to do the hang-gliding—I guess we'll just have to leave it for another day. Don't throw those decorations out! We can leave them for another occasion down the line!
leave something for another occasion
and keep something for another occasionto hold something back for later. (Occasion can be replaced with time, day, person, etc.) Please leave some cake for another day. Don't eat all the cheese. Leave some for another occasion. I have to leave some of my earnings for next month.