How to calculate difference between wanted date and today with filters

Hello jereaallikko 

add a new column in Power Query with this formula

if _[Status]="Open" then Duration.TotalDays(Date.From(DateTime.FixedLocalNow())- [Request sent at]) else null

Here the complete example

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45Wcs7JL05NUdJRMjDUAyIjA6VYnWgl/4LUPJCYiZ6BKRYxCzQxQwM9IIKKIUy00DMwBovGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Status = _t, #"Request sent at" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Status", type text}, {"Request sent at", type date}}, "de-DE"),
    AddDurationOfOpenRequests = Table.AddColumn
    (
        #"Changed Type",
        "Duration if open",
        each if _[Status]="Open" then Duration.TotalDays(Date.From(DateTime.FixedLocalNow())- [Request sent at]) else null
    )
in
    AddDurationOfOpenRequests

Copy paste this code to the advanced editor in a new blank query to see how the solution works.

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Kudoes are nice too

Have fun

Jimmy