I am trying to create a plot, but since there are days in the following month, the plot shows the same week in 2 months (which I do wanna avoid). So I would like to create a CustomMonth where if the count(WeekNum[Week5]) >= 4 in JAN CustomMonth must show JAN for all the Week5.

WeekNum             Month    CustomMonth
1) Week5             JAN            JAN
2) Week5             JAN            JAN
3) Week5             JAN            JAN
4) Week5             JAN            JAN
5) Week5             FEB            JAN
6) Week5             FEB            JAN
7) Week5             FEB            JAN