Easter falls on the first Sunday after the Full Moon date, based on mathematical calculations, that falls on or after March 21. If the Full Moon is on a Sunday, Easter is celebrated on the following Sunday.
Although Easter is liturgically related to the beginning of spring in the Northern Hemisphere (March equinox) and the Full Moon, its date is not based on the actual astronomical date of either event.
Խորեն Սարգսյանի բլոգ 