How long does it take for an ospreys egg to hatch?

Our Osprey's at Osprey House Environmental centre in Dohles Rocks Queensland Australia, laid an egg on the 22nd and a second on the 25th May 2009 with one egg still active. We have been told that gestation is between 38 and 40 days, so here is hoping that we have a chick late June or early July.