X Day (or 10 Day) is a monthly event held on the tenth of every month. Each month has a different small event happen along with common things that come with every single month.
Applies each month
These gift tickets are used to get exclusive items. List here. These are picked up from a Puku npc holding a balloon in one of the 5 towns (Gatara, Orphea, Glen, Julet and Azlan). The location changes each month. You can get 1 ticket from them each month per character.
This month's location
Wind Town Azlan (F5)
Free Boss Card in the Magic Labyrinth
Nyan coin Sale
Only available for people who cleared V3