Private Declare Function GetUserDefaultLCID Lib "kernel32" () As Long

Private Declare Function GetLocaleInfo Lib "kernel32" Alias "GetLocaleInfoA" ( _
  ByVal Locale As Long, _
  ByVal LCType As Long, _
  ByVal lpLCData As String, _
  ByVal cchData As Long) As Long
  
Private Const LOCALE_SSHORTDATE = &H1F      ' Краткий формат даты.
Private Const LOCALE_SLONGDATE = &H20       ' Длинный формат даты
Private Const LOCALE_STIMEFORMAT = &H1003   ' Формат времени.
Private Const LOCALE_SDATE = &H1D           ' Разделитель даты.
Private Const LOCALE_STIME = &H1E           ' Разделитель времени.

Public Sub GetDateTimeSettings()
    Dim str As String *  100 
    
    GetLocaleInfo GetUserDefaultLCID, LOCALE_SSHORTDATE, str,  99 
    Debug.Print fnTrimNull(str)
    
    GetLocaleInfo GetUserDefaultLCID, LOCALE_SLONGDATE, str,  99 
    Debug.Print fnTrimNull(str)
    
    GetLocaleInfo GetUserDefaultLCID, LOCALE_STIMEFORMAT, str,  99 
    Debug.Print fnTrimNull(str)
    
    GetLocaleInfo GetUserDefaultLCID, LOCALE_SDATE, str,  99 
    Debug.Print fnTrimNull(str)
    
    GetLocaleInfo GetUserDefaultLCID, LOCALE_STIME, str,  99 
    Debug.Print fnTrimNull(str)
End Sub

Function fnTrimNull( _
  ByVal strValue As String) As String
    Dim intPos As Integer
    
    intPos = InStr(strValue, vbNullChar)
    
    Select Case intPos
        Case  0 
        Case  1 
            fnTrimNull = ""
        Case Is >  1 
            fnTrimNull = Left(strValue, intPos -  1 )
    End Select
End Function