M / Power Query Dynamic 25-Calendar-Months to Date Filter

Hello, PBI community. I am working on a way to filter imported data for dynamic date ranges.

This particular attempt aims to filter for only the month to date and the preceding 24 calendar-months. This is what I have come up with, so far (see code below). It works, but does anyone have a more elegant or efficient way of doing this?

Note that today's data is not needed. We only want everything for the 25-calendar-months up through yesterday. For instance, on 9/22/2020 I need the first date to be 9/1/2018 and the last date to be 9/21/2020, and on 1/1/2021 I need the first date to be 12/1/2018 and the last date to be 12/31/2020.

let
    Source = blah blah blah,
    navigation_step = blah blah blah,
    #"Filtered Rows" = Table.SelectRows(navigation_step, each Date.IsInPreviousNMonths([DayDate], 24) or Date.IsInPreviousNDays([DayDate], 30)),
    #"Removed Other Columns" = blah blah blah
in
    #"Removed Other Columns"

I previously tried using date add functions with DateTime.LocalNow, but that didn't work. I have since deleted it, but it was something like this:

#"Filtered Rows" = Table.SelectRows(navigation_step, each [DayDate] >= Date.AddMonths(Date.StartOfMonth(Date.AddDays(DateTime.LocalNow, -1)), -24)),

The data for this is not particularly important; this is more of a conceptual question. The data could be a calendar table or daily aggregations of data. One important consideration is that there may be too much data to be imported into the PBIX, so we want to only pull what is needed.

Thanks for your help!