从程序中获取错误的日期时间 VB.net

Question

I have a program that send me a time for any account.

For some people, the program sends the datetime to the database like 2020-05-17 11:33:00 .

For some people, the program sends the datetime to the database like 0000-00-00 00:00:00 .

A photo to prove this:

The code which get the datetime is:

Imports System.Globalization
Imports System.Net

    Public Shared Function GetNistTime() As DateTime
        Dim myHttpWebRequest = CType(WebRequest.Create("http://www.microsoft.com"), HttpWebRequest)

        Dim response = myHttpWebRequest.GetResponse()
        Dim todaysDates As String = response.Headers("date")
        Return DateTime.ParseExact(todaysDates, "ddd, dd MMM yyyy HH:mm:ss 'GMT'", CultureInfo.InvariantCulture.DateTimeFormat, DateTimeStyles.AssumeUniversal)
    End Function

So what is the solution? What can these people install on their machines to prevent this, like install .NET Framework 3.5 ?

I don't know if installing .NET Framework 3.5 can solve this problem!

I think it can solve the problem because I found it on my PC, and on another PC where I get the datetime like 0000-00-00 00:00:00 doesn't have it installed.

Answer 1

According to your saying, you should firstly verify if it's just due to problem related to .NET Framework 3.5 installation. If it isn't, then try this code:

Try
    Dim client = New TcpClient("time.nist.gov", 13)
    Dim myDateTime As Date

    Using streamReader = New StreamReader(client.GetStream())
        Dim response = streamReader.ReadToEnd()
        Dim utcDateTimeString = response.Substring(7, 17)

        Dim localDateTime = Date.ParseExact(utcDateTimeString, "yy-MM-dd HH:mm:ss",
                    CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal)

        myDateTime = localDateTime
    End Using

    MsgBox(myDateTime.ToString)

    Catch ex As SocketException
        MsgBox("Unable to connect to the time server.", "Connection Failed!")
End Try