Start of the period	End of the period	Due date
March	2012-01-01	2012-03-31	2012-04-30
June	2012-04-01	2012-06-30	2012-07-31
September	2012-07-01	2012-09-30	2012-10-31
December	2012-10-01	2012-12-31	2013-01-31