From Zelda Wiki, the Zelda encyclopediaMajora's Mask, the Final Day, also known as the Third Day, is the last of the three total days that Link has before the Moon crashes into Clock Town and destroys all of Termina. From the dawn of this day, the young hero and Tatl only have 24 hours left to complete whatever tasks they have yet to resolve.
The citizens of Clock Town are all now aware of the impending doom that is about to befall them, and the environment and theme of Clock Town once again reflect the desperate state of Termina: slight earthquakes have begun to unravel throughout the land at random times, and the Clock Town music has taken a darker tone along with a frantic rhythm. The majority of the townsfolk already have their plans of evacuation ready, and the knights, who are being forced to stay at their guard, are urging the remaining citizens to evacuate as soon as possible. The sky highly contrasts that of the First Day, for it is now covered with dark tones that illustrate the depressing and somber fate of Termina. Once night arrives, most of the shops will be closed, and the majority of the citizens will have evacuated to Romani Ranch in hopes of staying safe from the threat of the now-giant moon, turning Clock Town from a lively, cheerful place to a bleak, desolate town. Once it becomes the "Night of the Final Day", Link cannot use the Song of Double Time or dance with Pierre as neither will work.
Below is a chart showing most of the major events that occur during the Final Day, including the time, place, and a brief description of said event.
|Anytime||North Clock Town||Link can play Hide-and-Seek with the Bombers to obtain the Bombers' Notebook|
|Anytime||Road to Ikana Canyon||Link can give Shiro a Red Potion to receive the Stone Mask from him.|
|6:00 AM to 6:00 PM||Laundry Pool||A Stray Fairy is floating around the Laundry Pool. Link can take her to the Fairy's Fountain in North Clock Town to receive a Magic Meter or the Great Fairy's Mask|
|6:00 AM to 6:00 PM||Gorman Track||Link can challenge the Gorman Brothers to a horse race and receive the Garo's Mask if he wins.|
|6:00 AM to 6:00 PM||Cucco Shack||Link can obtain the Bunny Hood from Grog by turning his chicks into Cuccos|
|10:00 AM to 6:00 PM||Mayor's Residence||Mayor Dotour is having a stressful meeting about the Carnival of Time. Link can help him end the meeting by wearing the Couple's Mask in front of him and receive a Piece of Heart.|
|1:00 PM to 10:00 PM||Laundry Pool||The Man from Curiosity Shop is waiting at the back room of the Curiosity Shop to give Link the Special Delivery to Mama, as well as the Keaton Mask.|
|6:00 PM to 7:00 PM||Ikana Canyon||Kafei is waiting for Sakon to show up and enter his hideout to retrieve the Sun Mask. Link can go in with him when Sakon's Hideout opens and help Kafei recover his stolen mask from the thief.|
|6:00 PM to 6:00 AM||Ikana Graveyard||Stalchildren will be monitoring a graveyard. If Link asks them to open it, he can find Dampe below it and play a digging minigame to obtain an empty bottle.|
|6:00 PM to 6:00 AM||Post Office||The Postman is still at his Post Office since evacuation isn't part of the schedule. Link can help him flee town by giving him the Special Delivery to Mama and receiving the Postman's Hat in return.|
|6:00 PM to 6:00 PM||Milk Bar||Madame Aroma can be found drowning her sorrows at the Milk Bar. Link can hand-deliver Kafei's letter to his mother to ease her worries and receive a bottle full of Chateau Romani as a reward.|
|6:00 PM to 6:00 AM||East Clock Town||A Stray Fairy is floating around East Clock Town. Link can take her to the Fairy's Fountain in North Clock Town to receive a Magic Meter or the Great Fairy's Mask|
|10:00 PM to 6:00 AM||Curiosity Shop||If Link stopped Sakon from robbing the Old Lady from Bomb Shop on the night of the First Day, the All-Night Mask will go up for sale at the Curiosity Shop.|
|12:00 AM||South Clock Town||The Clock Tower's entrance opens, signaling the start of the Carnival of Time. Link can climb the tower to face off with the Skull Kid.|
|12:00 AM to 6:00 AM||Stock Pot Inn restroom||Link can give ??? a Title Deed or a letter to receive a Piece of Heart.|
|12:00 AM to 6:00 AM||Termina Field||Kamaro is found dancing atop the rocks near the Snowhead entrance. Link can heal his soul to receive Kamaro's Mask.|
|4:30 AM||Stock Pot Inn Employee's Room||After much waiting, Kafei shows up at the Employee's Room to meet Anju, where the two lovers combine both of their masks to make the Couple's Mask. If Link witnesses this event, they will give the young hero the newly-formed mask as a gift of gratitude. (This requires retrieving the Sun Mask from Kafei's hideout.)|
|6:00AM||Anywhere||If Link has not stopped the Moon or played the "Song of Time", the moon falls upon Clock Town, killing him and all of the inhabitants of Termina.|