Imports System.Globalization
Dim provider As CultureInfo = CultureInfo.InvariantCulture
Dim standardFmts As String() = {"d", "D", "f", "F", "g", "G", "m", "o", "R", "s", "t", "T", "u", "U", "y"}
Dim customFmts As String() = {"yyyy/MM/dd", "h:mm:ss.ff t", "d MMM yyyy", "HH:mm:ss.f", "dd MMM HH:mm:ss", "\Mon\t\h\: M", "HH:mm:ss.ffffzzz"}
Console.WriteLine("Today's date is {0}.", Date.Today.ToString("MM/dd/yy", CultureInfo.InvariantCulture))
dateString = "3/23/2017 7:34:23 PM"
dateTime = DateTime.Parse(dateString, provider)
For Each standardFmt As String In standardFmts
Console.WriteLine("{0}: {1}", standardFmt, dateTime.ToString(standardFmt))
For Each customFmt As String In customFmts
Console.WriteLine("'{0}': {1}", customFmt, dateTime.ToString(customFmt))
Catch __unusedFormatException1__ As FormatException
Console.WriteLine("{0} is not in the correct format.", dateString)
Console.WriteLine(dateTime)