ILR calculating period

Hi , I need some help, if some body knows the answer.
tier1 visa date 30 march 2009 for 2 years.
tier 1 visa extension date 8 march 2011 for 3 years.

when is the earliest I can apply for ilr.
is it 28 days before 30 march 2014 or
is it 28 days before 8 march 2014.

thanks

28 days before 30th March 2014.
cheers
vr