IF THEN Formula Help

[cddexcel]

Hello. I'm looking for assistance with an IF THEN formula with regard to dates.
For example, if I have a date of 12/19/24 and I only want the next Monday date to populate, how would I code this? I have a drop down list of Monday or Thursday in my spreadsheet and depending on which is chosen as well as the initial date, I want the following Monday or Thursday date to populate in the cell.
Example: Date is 1/3/24 (in it's own cell) and I choose Monday in the drop down list (in it's own cell). What should the formula be so that 1/8/24 populates?
Thank you!

 

[iggydarsa]

Assuming your date is on A1, and Monday/Thursday flag is on B1 then

=IF(B1="Monday",IF(WEEKDAY(A1)=1,A1+1,(9-WEEKDAY(A1))+A1),IF(B1="Thursday",IF(WEEKDAY(A1)<5, (5-WEEKDAY(A1))+A1, (12-WEEKDAY(A1))+A1),""))

 

[kevin9999]

Another option:

Book1
	A	B
1	12/20/23	Monday
2
3	12/25/23
Sheet1

Cell Formulas
Range	Formula
A3	A3	=A1+(7-WEEKDAY(A1,IFS(B1="Monday",2,B1="Thursday",14))+1)

Cells with Data Validation
Cell	Allow	Criteria
B1	List	=$D$1:$D$2

Book1
	A	B
1	12/20/23	Thursday
2
3	12/21/23
Sheet1

Cell Formulas
Range	Formula
A3	A3	=A1+(7-WEEKDAY(A1,IFS(B1="Monday",2,B1="Thursday",14))+1)

Cells with Data Validation
Cell	Allow	Criteria
B1	List	=$D$1:$D$2