Sub ConvertDateFormatWithArray() Dim lastRow As Long Dim dateValues As Variant Dim convertedDates() As Variant Dim i As Long Dim yyyy As String Dim mm As String Dim dd As String ' 最終行を取得 lastRow = Cells(Rows.Count, "A").End(xlUp).Row ' A列の値を配列に読み込む dateValues = Range("A1:A" & lastRow).Value ' 出力用の配列…