Excel glitch? (Userform Textbox = Format, "Date")

Good day,
I just want to point out a small glitch or am I doing something wrong?
I have the following code that makes my Textbox3 from my Userform add the date format to “YYYY-MM-DD”

I came across yesterday a weird date glitch... When I selected 2013-11-12 it gave me 2013-12-11 but this means December 11, 2013 I want November 12, 2013. Today it works perfect and it writes down the code in accordance to the code, but still doesn’t take the November 12, 2013... Why?
Userform Code:

Private Sub TextBox3_Change()
TextBox3.Value = Format(TextBox3.Value, "YYYY/MM/DD")
End Sub

Private Sub TextBox3_Enter()
    frmne.TextBox3.Value = ""
    frmCalendar2.Show
End Sub

Note: Plus my Column is set to Custom "YYYY-MM-DD"