Dim PurchaseDate = Loan.Fields("3567").Value
Dim firstPmtDate = Loan.Fields("3570").Value
Dim endDate As Date
Dim beginDate As Date
Dim beginDay = Day(beginDate)
Dim endDay = Day(endDate)

'Find the endDate & beginDate from PurchaseDate
If Day(PurchaseDate) < 14 Then
    endDate = firstPmtDate
    beginDate = PurchaseDate
Else
    endDate = Month(DateAdd("m", -1, firstPmtDate)) & "/" & "01" & "/" & Year(DateAdd("m", -1, firstPmtDate))
    beginDate = PurchaseDate
End If

'Set endDay = 30 if beginDate and endDate are the last day of February
If Month(beginDate) = 2 And (beginDay = 28 Or beginDay = 29) And Month(endDate) = 2 And (endDay = 28 Or endDay = 29) Then
    endDay = 30
End If

'Set beginDay = 30 if endDate is last day of February and beginDate is on the 31st
If beginDay = 31 And Month(endDate) = 2 And (endDay = 28 Or endDay = 29) Then
    beginDay = 30
End If

'Set endDay = 30 if beginDate is on the 30th and endDate is on the 31st
If beginDay = 30 And endDay = 31 Then
    endDay = 30
End If

'Calc to find the # of Interest Accrued Days(3581)
Dim days = ((Year(endDate) - Year(beginDate)) * 360 + (Month(endDate) - Month(beginDate)) * 30 + (endDay - beginDay)) * -1