24th June 2012 - 28 days is 27th may - a Sunday thou, so say 28th may is the earliest you could apply for ILR, the latest a few days before you visa expires , say 18th July 2012
if your going in April and you don't think you'll be back b4 18th July then i think you should apply for FLR (m) b4 you go, i would need to check, but i'm sure you could apply for FLr say in jan, so even if they take 3 months to process it you should have it b4 april.. if you've not done the life in uk test, good reason to ask for flr is that you couldn't pass the test in time.
