Unlock Jester Hat
Set you DS clock to April 1st (April Fools Day) and play the mission "Rookie on the Rocks" Play the Mission all the way until you see Rookie on the other side of the river. There will be a box, click it and you will get a Jester Hat! Note: You must beat all 13 mission before doing this.
When you change you DS's clock you will get new missions, a few of these mission have items in the catalog only during that day. Also, there are a few free items during that day.
Unlockable: - How to Unlock:
"Deliver the Presents" Mission - Change Date to December 25th
"Flower Hunt" Mission - Change Date to April 1st
"Halloween Party" Mission - Change Date to October 31st
"Summer Party" Mission - Change Date to June 21st
April Items in Catalog - Change Date to April 1st
Fiesta Hat on Frozen Pond - Change Date to June 21st
Fish Costume in Lodge Attic - Change Date to October 31st
Ice Skates on the Iceberg - Change Date to December 25th
June Items in Catalog - Change Date to June 21st