Use Single Processing Date for Calculations

[Anonymous]

I'm pretty new to Power BI and this may be an obvious item for many of you, but would greatly appreciate the help.  

I have a set of data that is loaded each night after the day's processing.  The data includes information on customers and purchases.  One of the measurements I need to create is the Days Since Customer Added.  I have a table with the date that a customer registered and need to compare that to the Processing Date for the platform that comes in on table with one row of data and one column (cannot use system date/time, have to use the value from the control table).  

Simple Structure - Customers 

Customer Number	Date Registered
100	3/1/2021
101	3/15/2021
102	4/1/2021
103	4/15/2021

Processing Date Table

System Processing Date

6/1/2021

What I need is a measure or a column that does a DATEDIFF between the Date Registered value and the System Processing Date value.  If adding new column I'd need it to look like this....

Customer	Date Registered	Days Since Registration
100	3/1/2021	92
101	3/15/2021	78
102	4/1/2021	61
103	4/15/2021	47

[amitchandak · Accepted solution]

@Anonymous , Is there relation between two table or a common column ?

if not try like

a new column in table 1

= datediff([date registered], max(Table[System Processing Date]), day)

if there is a common column, get the value first, refer to these methods

refer 4 ways to copy data from one table to another
https://www.youtube.com/watch?v=Wu1mWxR23jU
https://www.youtube.com/watch?v=czNHt7UXIe8

[Anonymous]

Thanks!  using the Max function worked!