That will only work if he's gotten a sword to activate the Owl Statues... he has to go a full "3 days" and get his Ocarina first (from Skull Kid) before he can try that.
actually, he dosent have to wait the full 3days, in the observetory, or the shop next to the curiousity shop (i forgot the name) and talk to the scarecrow, and each time u talk to him, you can go to the next 12 hour period!
Hence my putting "three days" in quotes. But if it's his first run through, he will need to at least get the Moon Tear so he can access the Deku shooter to get to the clock tower. Otherwise that time will be wasted when the moon lands on his head.