2013-06-01 明日は 何日? Private Function tomorrow(nyear As Integer, nmonth As Integer) As Integer tomorrow = DateDiff("d", DateSerial(nyear, nmonth, 1) - 1, Date + 1) End Function VBE よりも Excel で書いたほうが簡単だった =TODAY()+1-DATE(B1,B2,0)