Automatically it turns from winter to spring if you beat the snowhead temple boss Goht. There are many things you can do in the spring start looking around to find out.
The last boss in Majora's Mask is Majora itself.
you have to beat goht the boss
In the stone tower temple boss room. But you can also use it in any other boss battle once you have the mask =)
You need the giants mask that you find in the temple and you must attack its head or its tail
You Can't. Feirce Deity's mask is only for Boss battles Ie: Major, Gyorg, Odalawa. You cannot where it outside of a boss battle.
beat the first dungeon mid boss
By defeating the mini-boss in Snow Peak Temple you are rewarded the Fire Arrows
if by the second time you mean 1st day again just go inside snowhead temple and walk into the green glowing thing and select yes beat the boss and spring time
its about 30x but when you do stone tower temple you get the giants mask and go to the boss room (with magic) and put on the giants mask and WHAM your huge (tall)
If you mean Zelda, you don't find her in Majora's Mask. However, You can find the Deku Princess after defeating Oldowa, the first boss of the game in Woodfall Temple.
complete all 4 temples and go to the tower at midnight. play oath to order. continue from there.
The only time the giants mask is absolutely needed is when you fight the boss of the stone Tower temple, Twinmold. you need to giants mask because Twinmold fights at a higher height than links normal height. When this happens you are unable to z target. If you put on the giants mask outside of a boss room, the game will freeze. Other than that the giants mask is useless.