How to count an ID over a specific timeframe

[arolon2]

I have a table (Roster) that includes IDs number and dates. What I am trying to do is count is the amount of occurances of that ID from the date listed the row until a week later.

UniqueID	DateDay	What I want
1	1/1/2020	2
1	1/3/2020	2
1	1/8/2020	1
1	2/14/2020	1
2	1/1/2020	1
2	2/1/2020	1

I tried the follwing but was unsuccesful. How should I be handling the second part of the filter to get be the correct timeframe?

IDCOUNT = 
VAR CurrentID = Roster[UniqueID]
VAR CurrentWeek = Roster[DateDay]
VAR NextWeek = DATEADD(Roster[DateDay],7,DAY)
RETURN
COUNTROWS(
     FILTER(
     Roster,
     CurrentID = Roster[UniqueID] &&
     (CurrentWeek >= Roster[DateDay] || CurrentWeek <= NextWeek)
     )
)

[az38 · Accepted solution]

Hi @arolon2 

DATEADD() is a very tricky function https://docs.microsoft.com/en-us/dax/dateadd-function-dax

The result table includes only dates that exist in the dates column.

  create a column

IDCOUNT = 
VAR CurrentID = Roster[UniqueID]
VAR CurrentWeek = Roster[DateDay]
VAR NextWeek = Roster[DateDay] + 7
RETURN
COUNTROWS(
     FILTER(
     Roster,
     CurrentID = Roster[UniqueID] &&
     CurrentWeek <= Roster[DateDay] && Roster[DateDay] < NextWeek
     )
)