Hi Manny,
If you have periodic model and there is no data in June then for YTD measure you will have in June:
P&L: same value as YTD May (YTD June - YTD May=0)
BS: nothing - same as with Periodic measure, because BS - always YTD
Vadim
P.S. BS: nothing - simply means that you have no value in June or it's equivalent to zero value!