Simplify the following text for a Grade 6 native English-speaking person.
Original: There are two holidays ( Eids ) in the Islamic calendar , Eid ul-Fitr and Eid ul-Adha during which there are special prayers held at mosques in the morning .
Simplified: There are two large holidays ( Eids ) in the Islamic calendar . During these days , there are special prayers at mosques in the morning .