Filtering the number of days between today and a specific date

[Berl21]

Hi,

I need to obtain the following number as a measure for me to do some additional calculations: number of days between today and a specific date within the data set.

I have added a calculated column in my date calendar to get the time difference in days between today and all the available days. Then I made another column with a marker for the date I have to take into account (not the first or last date of the dataset, so I can't use MIN or MAX as a get around). 

I can make a card with this as long as I use an additional filter to the visual (filter set on the 2nd column I mentioned). To get the same number as a measure, I thought I could use the following filter:

The error message I get doesn't make sense as of now. 

How can I get around this?

Thanks,

Pauline.

[Berl21 · Accepted solution]

@johnt75 I tried this just now but it doesn't seem to work. 

However, I did find the solution just now as well. It is way easier than all I could think of 😄 

Days since official start =

CALCULATE(

COUNTROWS(

DATESBETWEEN(DateTable[DayDate], DATE(2022,04,20), TODAY()

)))

[johnt75]

I think you could use

# of days =
VAR startDate =
    CALCULATE ( SELECTEDVALUE ( 'Date'[Date] ), 'Date'[Start date] = "Start date" )
RETURN
    DATEDIFF ( startDate, TODAY (), DAY )