Adar 11 Nissan 5784 14th day - Monday 22/4/2024 Passover
Adar 11 Nissan 5784 15th day - Tuesday 23/4/2024 First day of unleavened
Adar 11 Nissan 5784 21st day - Monday 22/4/2024 Seventh day of unleavened

The Jews moved the Passover from the 14th to the 15th. I guess they don't want to be associated with the crucifying of Jesus on the 14th.