Requirements
You have to have beaten the second level and gotten your horse to do this side-quest.
Masks Needed
Garo mask, Bunny hood, Stone mask, and Romani mask.
Masks Obtained
Kafei mask, Keaton mask, and Couple mask.
If you have not beaten the third level: After you get your horse, ride to ikana and get the stone mask by talking to the invisible guard in the middle of the ring of stones by the cliff. Also make sure you get the Garo mask by racing the Gorman brothers, and get the Romani mask by saving the cows and guarding the milk cart. Having the bunny hood helps too. Lastly, you have to have the hookshot or you can't finish the quest.
If you have beaten the third level: Ride to ikana and shoot the water on the river with ice arrows. Jump across to the other side of the dock and hookshot up to the owl statue. Hit it with your sword. You're ready to start the quest! Just make sure you have everything from the previous paragraph also.
Dawn of Day 1
6:00- Have the bunny hood and ocarina in your c-slots. If you have beaten the third level, go outside the stock pot inn and wait. If you have not beaten the third level, go to Termina Field and call your horse. Put on the stone mask now if you want. Ride it to Ikana and when you get to the cliff with the hooded guy, put on the Garo mask to make a tree appear on the top. Teleport back to clock town and go outside the stock pot inn.
8:00- This is optional. Go down the hallway downstairs until you get to the first door. Have grandma read you a two hour story. Make sure it is around 8, no later.
10:00- Run over to the mayor's office, the building at the very north of east clock town. Go to the door on the right, and talk to the big lady. She will give you the Kafei mask. Put the Kafei mask in one of your c-slots. Run back to the stock pot inn and wait at the counter.
2:00- Talk to anju without the Kafei mask on, and tell her you have a reservation. She will give you the key. Wait until the postman comes in and talks to anju and leaves. Talk to anju again with the Kafei mask on. She will schedule a meeting with you at 11:30.
2:30- You should be done with that by now. Play the song of double time.
Night of Day 1
6:00- You can do whatever you want, just keep track of time. If you don't want to do other things, then go to the kitchen in the back of the stock pot inn and wait there.
11:30- Anju should be entering the room around now.
12:00- Talk to anju, and she will give you a letter. Replace the Kafei mask in your c-slot with the letter. Run outside to the nearest mail-box and press A to it. Put the letter in it and you're done. Play the song of double time.
Dawn of Day 2
6:00- Do whatever you want for now, just keep track of time.
8:00- If you want, you can go over to the stock pot inn and have grandma read you a two hour story.
10:00- You still have time to do whatever you want.
2:00- Run over to the laundry pool and wait by the brown door at the end.
3:00- The postman will arrive, and Kafei will come out of the door to get the mail. Go inside the house and run up to the top.
4:00- Kafei will enter the house now. Talk to him and say you can keep a secret. He will give you a pendant. Run over to the stock pot inn, and talk to anju. Give her the pandant.
5:00- You should be done with that by now. Play the song of double time.
Night of Day 2
6:00- Nothing to do until day 3. Play the song of double time again.
Dawn of Day 3
6:00- Do whatever you want, just keep track of the time.
12:00- Head over back to the laundry pool and wait.
1:00- Enter the house and run up to the top. The shop owner guy will be in there and he will give you the Keaton mask and a letter. Put the letter in your third c-slot. Run over to the milk bar, the building across from the stock pot inn. Take off the bunny hood and replace it with the Romani mask. Put on the Romani mask. While standing outside of the milk bar, play the song of inverted time. It is important to play that because you will need time in the next part. Now play the song of double time and get ready to hurry.