bool = IsInsideMonth(nDate, nDayValue)
This macro function can be used to determine if n_TokenDate is inside or outside the month in a monthly grid.
bIsInsideMonth = IsInCurrentMonth(n_TokenDate - (n_TokenDayValue mod 42) + 8)
Internally, this function makes use of the fact that in a monthly diary, the 8th day of any block of 42 days is always garanteed to be within the current month.