マクロ2

１ヶ月12シート作成

Sub CreateFiscalYearSheets()

Dim startDate As Date
Dim startYear As Long
Dim startMonth As Long
Dim i As Long
Dim ws As Worksheet
Dim newWS As Worksheet
Dim targetDate As Date

'★C3 の日付を年度開始として取得
startDate = Range("C3").Value
startYear = Year(startDate)
startMonth = Month(startDate)

'原紙シート
Set ws = ThisWorkbook.Worksheets("原紙")

For i = 0 To 11
    
    '対象月の1日
    targetDate = DateSerial(startYear, startMonth + i, 1)
    
    '原紙シートをコピー
    ws.Copy After:=Sheets(Sheets.Count)
    Set newWS = ActiveSheet
    
    'C3 に対象月の1日を入力
    newWS.Unprotect
    newWS.Range("C3").Value = targetDate
    newWS.Protect
    
    'シート名を YYYY.MM にする
    newWS.Name = Format(targetDate, "yyyy.mm")
    
Next i

End Sub

C3
=DATE(B2,4,1)

EOMONTH関数使ってるとこがB2