.NET DateTime.Now returns incorrect time when time zone is changed

Question

This problem occurred during daylight saving time change. After the change occurred, we\'ve noticed that our server application started writing into the log incorrect time -

Answer 1

In my project I needed to Reset a series of variables if the Time (or Timezone) was changed. So that I could get the fact this event occurred I ended up using a WindowsMessageFilter.

I'm using .Net 2.0 so I couldn't use (or maybe i'm looking in the wrong places for) the ClearCachedData so I used this approach with the help of a little reflection.

    Private mTZChangeFilter As WindowsMessageFilter


    mTZChangeFilter = New WindowsMessageFilter()
    AddHandler mTZChangeFilter.TimeChanged, AddressOf onTimeChanged

    Application.RemoveMessageFilter(mTZChangeFilter)


Public Class WindowsMessageFilter
    Implements IMessageFilter

     _
    Public Function PreFilterMessage(ByRef m As System.Windows.Forms.Message) As Boolean Implements System.Windows.Forms.IMessageFilter.PreFilterMessage
        ' Debug.Print(m.Msg.ToString)
        If m.Msg = 30 Then
            ResetTimeZone()
            RaiseEvent TimeChanged(Me)
        End If
    End Function

    Private Sub ResetTimeZone()
        Dim tz As Type = GetType(System.TimeZone)
        Dim mth As System.Reflection.MethodInfo

        Try
            mth = tz.GetMethod("ResetTimeZone", BindingFlags.NonPublic Or BindingFlags.Static)
            mth.Invoke(mth, Nothing)
        Catch ex As Exception
            Debug.Print(ex.ToString)
        End Try
    End Sub 

end class