Find previous start and end date base on current Start & End Date and Week number?

[Sochen]

How to find Start & End date of previous year (Yellow Highlight) base on current Start & End Date and Week number?

Book5
	A	B	C	D
1	Example	Start Date	End Date	Week Number
2	1	Monday, December 27, 2021	Sunday, January 2, 2022	52
3		Monday, December 21, 2020	Sunday, December 27, 2020	52
4
5	Example	Start Date	End Date	Week Number
6	2	Monday, December 25, 2023	Sunday, December 31, 2023	52
7		Monday, December 26, 2022	Sunday, January 1, 2023	52
Sheet1

Cell Formulas
Range	Formula
D6:D7,D2:D3	D2	=ISOWEEKNUM(B2)
C3	C3	=B3+6

 

[Legacy 143009]

B3:

=(B2-365)-WEEKDAY(B2-365,2)+1

C3:

=(C2-365)-WEEKDAY(C2-365,2)

 

[Sochen]

B3:

=(B2-365)-WEEKDAY(B2-365,2)+1

C3:

=(C2-365)-WEEKDAY(C2-365,2)

Hi Sir,

Thank you for your response. But this formula is not working in example 2 because it shows different week number.

 

[Legacy 143009]

OK sorted. B3:

=DATE(YEAR(B2)-1,1,-2)-WEEKDAY(DATE(YEAR(B2)-1,1,3))+ISOWEEKNUM(B2)*7

C3 is a bit more tricky:

=DATE(YEAR(C2)-(1+FLOOR(1/MONTH(C2),1)),1,-2)-WEEKDAY(DATE(YEAR(C2)-(1+FLOOR(1/MONTH(C2),1)),1,3))+ISOWEEKNUM(C2)*7+6