Just check "All earnings available at 28 Feb 2010 23:59:59 " anytime in February and you will get ALL earnings available at 28 Feb 2010 23:59:59. You get them 15th next month (March).
Please note that you have to do this every month, but it doesn't matter if you do it at 5th or 25th day in particular month. You still get paid ALL your earnings from last month at 15th the next month. ( if you check that checkbox. )