解释一个问题
firstday = Year(Date) & "-" & Me.comMonth.Text & "-1"
days = DateDiff("d", Year(Date) & "-" & Me.comMonth.Text & "-1", Year(Date) & "-" & Me.comMonth.Text + 1 & "-1")
lastday = Year(Date) & "-" & Me.comMonth.Text & "-" & days
