TimeZone

Day and night come in different phases across the planet. We have time zones so that no one needs to wake up at midnight local time.

With TimeZone.CurrentTimeZone, we can access the current time zone information on the system. This depends on the system's configuration. We can also use conversions based on the time zone.

An example

Here we get the current time zone with TimeZone.CurrentTimeZone, a shared property in VB.NET. We see the computer is located in the Pacific Standard Time zone.

Module Module1

    Sub Main()
        Dim zone As TimeZone = TimeZone.CurrentTimeZone

        ' Get standard and daylight names.
        Dim standard As String = zone.StandardName
        Dim daylight As String = zone.DaylightName
        Console.WriteLine("STANDARD NAME: " + standard)
        Console.WriteLine("DAYLIGHT NAME: " + daylight)

        ' Get local and universal time for DateTime.Now.
        Dim local As DateTime = zone.ToLocalTime(DateTime.Now)
        Dim universal As DateTime = zone.ToUniversalTime(DateTime.Now)
        Console.WriteLine("LOCAL TIME: " + local)
        Console.WriteLine("UNIVERSAL TIME: " + universal)
    End Sub

End Module
STANDARD NAME: Pacific Standard Time
DAYLIGHT NAME: Pacific Daylight Time
LOCAL TIME: 7/7/2018 7:11:49 AM
UNIVERSAL TIME: 7/7/2018 2:11:49 PM

Notes, ToLocalTime

We call ToLocalTime to convert a DateTime into the local time zone. In this program, the local time was the same as DateTime.Now, as Now returned a local time.

Notes, ToUniversalTime

This takes a DateTime and converts it to a universal time—one that is not based on local time. A new DateTime is returned.

Daylight changes, and time zones, are a complex subject. But with the TimeZone.CurrentTimeZone property in VB.NET we gain insight into how dates and times are affected.