Monthly Totals For Previous Quarter

[supportsvc]

Hello,
I can't seem to figure out how to get
First month of the previous quarter total
Second and Third

I have the following but the totals aren't correct UNLESS it's ran in the 1st month of the current quarter for the previous quarter data.

here are the snippets

Sum(IIf(Month([CheckDate])=Month(Date())-3,[WagesSubjToEmployerUI],0)) AS Mth1, Sum(IIf(Month([CheckDate])=Month(Date())-2,[WagesSubjToEmployerUI],0)) AS Mth2, Sum(IIf(Month([CheckDate])=Month(Date())-1,[WagesSubjToEmployerUI],0)) AS Mth3

HAVING (((Year([CheckDate]))=[Forms]![frmProcessing]![CurrentYear]) AND ((DatePart("q",[CheckDate]))=DatePart("q",Date())-1)

How/what can be changed so Mth1 is actually the First month of the previous quarter, etc ...?

Since we're in May and still running Quarter 1 data, the Mth1, Mth2, Mth3 are incorrect now. They were correct when ran last month in April.

 

[supportsvc]

I think I found a solution

Sum(IIf(((Month([CheckDate])-1) Mod 3)+1=1,[WagesSubjToEmployerUI],0)) AS Mth1, Sum(IIf(((Month([CheckDate])-1) Mod 3)+1=2,[WagesSubjToEmployerUI],0)) AS Mth2, Sum(IIf(((Month([CheckDate])-1) Mod 3)+1=3,[WagesSubjToEmployerUI],0)) AS Mth3