Calculated Column - DATEDIFF - Days Since Promo Start

[tc97]

Hi, 
I have two tables - one for sales, and one for promotions we run. 

Sales table includes following columns:

OrderID

OrderDate

PromoCode

OrderValue

Promotions table consists of only two columns:

PromotionCode

PromoStartDate

I'm looking to add a calculated column 'PromotionDay' to the Sales table to return how many days into the Promotion the order was placed. Is this relatively simple to calculate?

example below:

Promotion Table includes record: PromotionCode = 'SPRING22', PromoStartDate = '01 March 2022'

Sales Table would have the below record

OrderID	OrderDate	PromoCode	OrderValue	PromotionDay
000987	05 March 2022	SPRING22	£150.99	5

Thanks in advance.

[tamerj1 · Accepted solution]

Hi @tc97 
Please try

PromotionDay =
DATEDIFF ( RELATED ( Promotions[PromoStartDate] ), Sales[OrderDate], DAY )

[tc97]

That was nice and easy! Thanks so much!!