there are functions, InYearToDate InMonthToDate you can use to flag your date; the flags can be used in chart for MTD, YTD
from QlikView online help
InMonthToDate (date, basedate , shift)
returns true if date lies inside the part of month containing basedate up until and including the last millisecond of basedate. The month can be offset by shift. Shift is an integer, where the value 0 indicates the month which contains basedate. Negative values in shift indicate preceding months and positive values indicate succeeding months.