Calculate Days between OrderDate per Customer where Order date is in the same Column???

Sorry Matt,

Got it working not sure if it was me having the .Date on the date column and i selected CustomerID for the Values bit, but got rid of the .Date and ID so its like the columns below and done manual calculations to verify the data its outputing and its working now

So this is what i ended up with;

First Order = CALCULATE(FIRSTDATE(TableName[Date]),VALUES(Tablename[Date]))

Last Order = CALCULATE(LASTDATE(TableName[Date]),VALUES(Tablename[Date]))

Number of Orders = DISTINCTCOUNT(TableName[OrderID])

First to Last Date period = ((TableName[Last Order] - TableName[First Order])*1)

Today = Today()

Days Since Last Order = TableName[Today].[Date] - TableName[Order Date].[Date] * 1

Avg Order Period = divide(TableName[First to Last Date period],TableName[Number of Orders])

&

Difference = CALCULATE(MIN([Days Since Last Order]) - [Avg Order Period])

Then when Difference gets to 0 its time to call,

Seeing it like the above makes it so clear, Thanks Matt, Great Work !!!

Thanks,

J