In the margins: why does the date for Easter change every year?
Easter Sunday is the first Sunday after the full Moon, following the March equinox. It’s a bit of a calculation and here it is explained further…
An equinox is when the centre of our Sun is on exactly the same plane as Earth’s equator. The Earth’s axis isn’t tilted toward the Sun one way or the other and the hours of night and day are almost equal in length. Another thing to note at equinox is that sunrise is due east and sunset is due west. March’s equinox is on or around 22 March every year.
In 2017, the March equinox is on 20 March (at 6.29pm WA time). The full Moon after this date is on Tuesday, 11 April and therefore Easter Sunday is the following Sunday which is 16 April 2017!