Typically, each classroom celebrates just two (2) events with in-class parties-- Christmas/Winter and Valentine's Day. However, be sure to check with your class' teacher regarding other holiday/event celebrations as younger grades often celebrate more than just the two (2) designated holidays/events.  
(For instance, Halloween, Thanksgiving, Groundhog's Day, St. Patrick's Day, Easter/Spring, 100th Day of School, etc.) Also, be sure to inquire about End of Year celebrations.

***Important***

Food for Classroom Celebrations
Due to food allergies and various health issues, NO homemade food is allowed to be served at Classroom Celebrations.

All food must be store-bought with ingredients listed.  This, obviously, does not apply to fresh fruit & vegetables.  

Regarding sweets & treats, the Smart Snacks program was instituted by the government in 2014-2015, which meant that the Cafeteria could no longer sell ice cream.
The Smart Snacks program applies only to food that is sold or distributed by the school, including teachers & staff.  With that said, store-bought baked goods (cookies, cupcakes, donuts, etc.) and ice cream are allowed to be served at class parties, however parents should check with the teacher before bringing in such items. 

If you're looking for ideas regarding alternatives to food treats/rewards, please see the attached PowerPoint presentation .pdf, entitled Rewards Kids Will Crave, regarding the health benefits of not rewarding our children with food: Rewards Kids Will Crave