Turn off timezone DST adjustment in VB.NET? - asp.net

Question

fellow programmers. Recently i got a problem when the DST applied to my asp.net application.
Originally, i got my datetime converter as follow:
Private Function ConvertTimezone(convertDatetime As DateTime, zoneID As String) As DateTime
Dim timeZoneInfo As TimeZoneInfo = System.TimeZoneInfo.FindSystemTimeZoneById(zoneID)
Dim dataTimeByZoneId As DateTime = System.TimeZoneInfo.ConvertTime(convertDatetime, System.TimeZoneInfo.Local, timeZoneInfo)
Return dataTimeByZoneId
End Function
Which is running smoothly as i am expected. However, when daylight saving started, all stuff seems to went to the wrong way AS I LIST THE OPTION TO SELECT AS UTC - 12 TO UTC + 12 by getting the standard time and convert it using the above code.
For example, the problem i am facing is the shift of hours, before DST, My UTC - 5 is from Atlantic standard time ,but after DST it returns UTC - 4 now as .NET CONVERT IT BY ITSELF. The dropdown has gone wrong since then.
Is there anyway to turn the DST adjustment off? or any other work around can complement the offset? (No other library is allowed ,sorry fellows..)

Answer 1

I worked it around by parsing the UTC + x value where x is the offset
Private Function ConvertTimezone(convertDatetime As DateTime, zoneID As String) As DateTime
Dim desttimeZoneInfo As TimeZoneInfo
Dim dataTimeByZoneId As DateTime
If Not zoneID.Contains("GMT") Then
desttimeZoneInfo = System.TimeZoneInfo.FindSystemTimeZoneById(zoneID)
dataTimeByZoneId = System.TimeZoneInfo.ConvertTime(convertDatetime, System.TimeZoneInfo.Local, desttimeZoneInfo)
Else
dataTimeByZoneId = System.TimeZoneInfo.ConvertTimeToUtc(convertDatetime, System.TimeZoneInfo.Local)
dataTimeByZoneId = dataTimeByZoneId.AddHours(Double.Parse(zoneID.Substring(3)))
End If
Return dataTimeByZoneId
End Function