VB.Net Tutorial/Date Time/DateTime

DateTime.Parse(PM)

<source lang="vbnet">public class Test

  public Shared Sub Main
       Console.WriteLine(DateTime.Parse("12:00:00 PM"))
  End Sub

End class</source>

11/05/2007 12:00:00 PM

DateTime parse date and time by DateTimeFormatInfo

<source lang="vbnet">public class Test

  public Shared Sub Main
       Dim Provider As New System.Globalization.DateTimeFormatInfo()
       Console.WriteLine(Provider.AMDesignator())
       Console.WriteLine(DateTime.ParseExact("12:42", "hh:mm", Provider))
  End Sub

End class</source>

AM
11/05/2007 12:42:00 AM

DateTime Subtract

<source lang="vbnet">public class Test

  public Shared Sub Main
   Dim D As DateTime
   D = Now()
   Console.WriteLine(D.ToUniversalTime().GetType().Name)
   Console.WriteLine("UTC-LocalTime=" + D.ToUniversalTime().Subtract(D).ToString())
  End Sub

End class</source>

DateTime
UTC-LocalTime=07:00:00

Get Date from long integer

<source lang="vbnet">public class Test

  public Shared Sub Main
   Dim D As New DateTime(10000333333333333)
   Console.WriteLine("10000 ticks is " + D.Date())
  End Sub

End class</source>

10000 ticks is 09/09/0032

Get Hour from DateTime

<source lang="vbnet">Imports System Public Class Greeting

    Shared Sub Main()
       Dim dtCurrent As System.DateTime
       Dim iHour As Integer
       dtCurrent = dtCurrent.Now()
       iHour = dtCurrent.Hour
       If (iHour < 12) Then
           Console.Writeline("Good Morning!")
       End If
       If (iHour >= 12) And (iHour < 18) Then
           Console.WriteLine("Good Afternoon!")
       End If
       If (iHour >= 18) Then
           Console.WriteLine("Good Evening!")
       End If
   End Sub

End Class</source>

Good Afternoon!

Get UniversalTime from DateTime

<source lang="vbnet">public class Test

  public Shared Sub Main
       Dim D As DateTime
       D = Now()
   
       Console.WriteLine(D.ToUniversalTime().GetType().Name)
   
       Console.WriteLine("UTC-LocalTime=" + D.ToUniversalTime().Subtract(D).ToString())
   
       Console.WriteLine("Ticks since 12:00AM January 1, 1 CE="+ Now().Ticks().ToString())
  End Sub

End class</source>

DateTime
UTC-LocalTime=07:00:00
Ticks since 12:00AM January 1, 1 CE=633144833635000000

Timing code block

<source lang="vbnet">public class Test

  public Shared Sub Main
       Const TRIALS As Integer = 10000000
       Dim start_time As DateTime
       Dim stop_time As DateTime
       Dim elapsed_time As TimeSpan
       Dim i As Integer
       start_time = Now
       For i = 1 To TRIALS
       Next i
       stop_time = Now
       elapsed_time = stop_time.Subtract(start_time)
       Console.WriteLine(elapsed_time.TotalSeconds.ToString("0.000000"))
       start_time = Now
       For i = 1 To TRIALS
       Next i
       stop_time = Now
       elapsed_time = stop_time.Subtract(start_time)
       Console.WriteLine(elapsed_time.TotalSeconds.ToString("0.000000"))
   
  End Sub

End class</source>

0.015625
0.015625