G.B.
Easter is sometimes in March, sometimes in April, sometimes it is even in late April It is not on the same weekend all the time. It may just be that the next few years it is on that first weekend of April but that is not common.
It's on 8th April 2012, 31st March 2013, 20th April 2014, 5th April 2015, 27th March 2016, 16th April 2017.....
http://www.assa.org.au/edm.html
So it looks like he'd have the kids every other Easter except for this year and next year.