Date filter to load previous month if it is the first of the new month

Power Query
2

Hi @LASHBURN,

I feel you where so close to solving it…
See if this works for you. I used this Date table M code and named that query fxCalendar, next add a new blank query and paste in the code below.

let
    Source = fxCalendar(#date(2017, 1, 1), #date(2022, 12, 31), null, null, null, null),
    Today = #date(2021, 2, 1), //Date.From(DateTime.LocalNow()),
    FilterDates = Table.SelectRows( Source, each (if Date.Day(Today)=1 then Date.IsInPreviousMonth([Date]) else Date.IsInCurrentMonth([Date]) and [Date] < Today ))
in
    FilterDates

I hope this is helpful.