Private Sub 提前一个星期()
Dim date2 As Date = DateTimePicker2.Text
Dim nian, yue, ri As Integer
ri = date2.Day
yue = date2.Month
nian = date2.Year
If ri > 7 Then
ri = ri - 7
Else
If yue - 1 = 2 Then
ri = ri + 28 - 7
yue = 2
Else
If yue = yue - 1 = 1 And yue = yue - 1 = 3 And yue = yue - 1 = 5 And yue = yue - 1 = 7 And yue = yue - 1 = 8 And yue = yue - 1 = 10 And yue = 1 Then
ri = ri + 31 - 7
If yue = 1 Then
yue = yue + 12 - 1
nian = nian - 1
Else
yue = yue - 1
End If
Else
ri = ri + 30 - 7
If yue = 1 Then
yue = yue + 12 - 1
nian = nian - 1
Else
yue = yue - 1
End If
End If
End If
End If
DateTimePicker1.Text = nian & -yue & -ri
End Sub