Generate new rows based on Quarter Year table in Power Query

Hi WM117,

Sound and low code solution by tackytechtom 

However if you are set on "calculating" those dates, you can try something like this:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("TcqxDQAgCEXBXaw1UfgMYk3Yfw2J1euuuMxxz7JtPmq2DXZY8P/CF77whR/4gR/47Xo=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [QuarterYear = _t]),
    AddDates = Table.AddColumn(Source, "Custom", each 
        [
            Q = Number.From( Text.ToList([QuarterYear]){1} ),
            Y = Text.End( [QuarterYear], 4),
            M = List.Transform( List.Range( {1..12}, if Q = 1 then 0 else (Q-1) *3, 3 ), 
                (x)=> Date.ToText( Date.FromText( Text.From(x) & "-" & Y ), [Format="MMM/yy", Culture="en-US"] ))
        ][M] ),
    ExpandDates = Table.ExpandListColumn(AddDates, "Custom")
in
    ExpandDates

That will return a list with values you can expand, final result below.

I hope this is helpful

Hi, WM117 another text field solution

let
    Source = situation,
    quarters = [Q1 = {"Jan/", "Feb/", "Mar/"}, Q2 = {"Apr/", "May/", "Jun/"}, Q3 = {"Jul/", "Aug/", "Sep/"}, Q4 = {"Oct/", "Nov/", "Dec/"}],
    add = Table.AddColumn(
        Source, "MonthYear",
        (x) => List.Transform(
            Record.FieldOrDefault(quarters, Text.Start(x[QuarterYear], 2)),
            (w) => w & Text.End(x[QuarterYear], 2)
        )
    ),
    expand = Table.ExpandListColumn(add, "MonthYear")
in
    expand