Public Class clsFormatDateTime
 
    Public Sub Main()
        '****************************************************************************************
        ' Purpose: Returns a string representing the datetime.
        '
        ' Syntax: 	String.Format(datetime, formatspecifier)
        '
        ' Parameter1: datetime - Required - datetime value to be formatted
        '
        ' Parameter2: formatspecifier - required - format to be applied to date. 
        ' Here are custom format specifiers y (year), M (month), d (day), 
        ' h (hour 12), H (hour 24), m (minute), s (second),
        ' f (second fraction), F (second fraction, trailing zeroes are trimmed),
        ' t (P.M or A.M) and z (time zone).
        '
        ' Result: string - Returns a string reperesenting the datetime.
        '
        ' Quick Example:  Dim dt As New DateTime(2009, 12, 20, 20, 4, 8, _
        ' 101)
        ' ' Ways to format year: "9 09 009 2009"   year
        ' Console.WriteLine(String.Format("{0:y yy yyy yyyy}", dt))
        ' ' returns 9 09 009 2009
        '
        '**************************************************
        '        Custom DateTime Formatting
        '**************************************************
 
        Console.WriteLine("Custom DateTime Formatting:")
        'Here are custom format specifiers y (year), M (month), d (day), h (hour 12), H (hour 24), m (minute), s (second),
        ' f (second fraction), F (second fraction, trailing zeroes are trimmed), t (P.M or A.M) and z (time zone).
 
        'Following examples show how the format specifiers can be used.
        ' create date time 2009-12-21 20:04:08.101
        Dim dt As New DateTime(2009, 12, 20, 20, 4, 8, _
         101)
 
        ' Ways to format year: "9 09 009 2009"   year
        Console.WriteLine(String.Format("{0:y yy yyy yyyy}", dt))
 
        ' Ways to format month: "12 12 Dec December"  month
        Console.WriteLine(String.Format("{0:M MM MMM MMMM}", dt))
 
        ' Ways to format day: "21 21 Sun Sunday" day
        Console.WriteLine(String.Format("{0:d dd ddd dddd}", dt))
 
        ' Ways to format hour: "8 08 20 20"      hour 12/24
        Console.WriteLine(String.Format("{0:h hh H HH}", dt))
 
        ' Ways to format minute: "4 04"            minute
        Console.WriteLine(String.Format("{0:m mm}", dt))
 
        ' Ways to format second:  ' "8 08"            second 
        Console.WriteLine(String.Format("{0:s ss}", dt))
 
        ' Ways to format fraction of second: "1 10 101 1010"   sec.fraction
        Console.WriteLine(String.Format("{0:f ff fff ffff}", dt))
 
        ' Ways to format fraction of second: "1 1 101 101"   without zeros
        Console.WriteLine(String.Format("{0:F FF FFF FFFF}", dt))
 
        ' How to display am or pm: "P PM"            A.M. or P.M.
        Console.WriteLine(String.Format("{0:t tt}", dt))
 
        ' How to display timezone: "-6 -06 -06:00"   time zone
        Console.WriteLine(String.Format("{0:z zz zzz}", dt))
 
 
        '**************************************************
        '        Using date separator / (slash) and time sepatator : (colon).
        '**************************************************
        Console.WriteLine(vbCrLf)
        Console.WriteLine("Using date separator / (slash) and time sepatator : (colon):")
 
        'These characters will be rewritten to characters defined 
        'in the current DateTimeFormatInfo.DateSepa­rator and DateTimeFormatInfo.TimeSeparator.
 
 
        ' "20/12/09 20:04:08" - english (en-US)
        Console.WriteLine(String.Format("{0:d/M/yyyy HH:mm:ss}", dt))
 
        ' "20.12.2009 20:04:08" - german (de-DE)
        ' date separator in german culture is "." (so "/" changes to ".")
        Console.WriteLine(String.Format("{0:d/M/yyyy HH:mm:ss}", dt))
 
        '**************************************************
        ' Here are some examples of custom date and time formatting:
        '**************************************************
        Console.WriteLine(vbCrLf)
        Console.WriteLine("Here are some examples of custom date and time formatting:")
 
        ' month/day numbers without/with leading zeroes
        ' "12/20/2009"
        Console.WriteLine(String.Format("{0:M/d/yyyy}", dt))
 
        ' "12/20/2009"
        Console.WriteLine(String.Format("{0:MM/dd/yyyy}", dt))
 
        ' day/month names
        ' "Sun, Dec 20, 2009"
        Console.WriteLine(String.Format("{0:ddd, MMM d, yyyy}", dt))
 
        ' "Sunday, December 20, 2009"
        ' two/four digit year
        Console.WriteLine(String.Format("{0:dddd, MMMM d, yyyy}", dt))
 
        ' "12/20/09"
        Console.WriteLine(String.Format("{0:MM/dd/yy}", dt))
 
        ' "12/20/2009"
        Console.WriteLine(String.Format("{0:MM/dd/yyyy}", dt))
 
        '**************************************************
        '        Standard DateTime Formatting
        '**************************************************
        Console.WriteLine(vbCrLf)
        Console.WriteLine("Standard DateTime Formatting:")
        'In DateTimeFormatInfo there are defined standard patterns for the current culture. 
        'For example, property ShortTimePattern is string that contains value h:mm tt for en-US culture 
        'and value HH:mm for de-DE culture.
 
        'Following table shows patterns defined in DateTimeFormatInfo and their values for en-US culture. 
        'First column contains format specifiers for the String.Format method.
 
        'Specifier DateTimeFormatInfo property Pattern value (for en-US culture) 
        't ShortTimePattern h:mm tt 
        'd ShortDatePattern M/d/yyyy 
        'T LongTimePattern h:mm:ss tt 
        'D LongDatePattern dddd, MMMM dd, yyyy 
        'f (combination of D and t) dddd, MMMM dd, yyyy h:mm tt 
        'F FullDateTimePattern dddd, MMMM dd, yyyy h:mm:ss tt 
        'g (combination of d and t) M/d/yyyy h:mm tt 
        'G (combination of d and T) M/d/yyyy h:mm:ss tt 
        'm, M MonthDayPattern MMMM dd 
        'y, Y YearMonthPattern MMMM, yyyy 
        'r, R RFC1123Pattern ddd, dd MMM yyyy HH':'mm':'ss 'GMT' (*) 
        's SortableDateTi­mePattern yyyy'-'MM'-'dd'T'HH':'mm':'ss (*) 
        'u UniversalSorta­bleDateTimePat­tern yyyy'-'MM'-'dd HH':'mm':'ss'Z' (*) 
        '    (*) = culture independent 
 
        'Following examples show usage of standard format specifiers in String.Format method and the resulting output.
 
        ' "8:04 PM"                         ShortTime
        Console.WriteLine(String.Format("{0:t}", dt))
 
        ' "12/20/2009"                        ShortDate
        Console.WriteLine(String.Format("{0:d}", dt))
 
        ' "8:04:08 PM"                      LongTime
        Console.WriteLine(String.Format("{0:T}", dt))
 
        ' "Sunday, December 20, 2009"          LongDate
        Console.WriteLine(String.Format("{0:D}", dt))
 
        ' "Sunday, December 20, 2009 8:04 PM"  LongDate+ShortTime
        Console.WriteLine(String.Format("{0:f}", dt))
 
        ' "Sunday, December 20, 2009 8:04:08 PM" FullDateTime
        Console.WriteLine(String.Format("{0:F}", dt))
 
        ' "12/20/2009 8:04 PM"                ShortDate+ShortTime
        Console.WriteLine(String.Format("{0:g}", dt))
 
        ' "12/20/2009 8:04:08 PM"             ShortDate+LongTime
        Console.WriteLine(String.Format("{0:G}", dt))
 
        ' "December 20"                        MonthDay
        Console.WriteLine(String.Format("{0:m}", dt))
 
        ' "December, 2009"                     YearMonth
        Console.WriteLine(String.Format("{0:y}", dt))
 
        ' "Sun, 20 Dec 2009 20:04:08 GMT"   
        Console.WriteLine(String.Format("{0:r}", dt))
 
        ' "2009-12-20T20:04:08"             SortableDateTime
        Console.WriteLine(String.Format("{0:s}", dt))
 
        ' "2009-12-20 20:04:08Z"            UniversalSortableDateTime
        Console.WriteLine(String.Format("{0:u}", dt))
 
 
 
 
 
 
 
 
 
 
 
        Console.ReadLine()
    End Sub
End Class

Module Module1
 
    Sub Main()
 
 
        Dim myclsFormatDateTime As New clsFormatDateTime
        myclsFormatDateTime.Main()
 
 
 
    End Sub
 
End Module