Financial Period start date

[AliBb]

How can I set a period number based on a Jan - Dec Financial year where the month end date is the last Friday in the month unless the last Day of the month falls on a wed or a Thursday in which case it is the Fri of that week
For eg
Period 4 is 31st Mar 18 - 27th Apr 18
Period 5 is 28th Apr - 1st June
Period 6 is 2nd June - 29th June

 

[Yongle]

Try this which is based on formula posted in your other thread

=IF(AND(MONTH(A2)=1,DAY(A2)<7),1,
IF(AND(MONTH(A2)=12,DAY(A2)>7),12,
MOD(MONTH($A2)-1+AND(DAY($A2)>27,WEEKDAY($A2,13)>3,DAY($A2)-WEEKDAY($A2,13)>23)-AND(DAY($A2)<3,WEEKDAY($A2,14)<3,DAY($A2)<=WEEKDAY($A2,14)),12)+1))