Formatting

Dim sResult As String 
sResult = System.String.Format("{0:MM\/dd\/yyyy}", System.DateTime.Now()) 
sResult = "01/06/2002" 

Formatting Dates

Dim dtDateTime As System.DateTime 
dtDateTime As New System.DateTime(2002, 1, 6, 18, 30, 20) 

ToLongDateString

This format does not always display correctly and will depend on local settings.
It only displays the following format when the settings are US

System.DateTime dtDateTime; 
dtDateTime = new System.DateTime(2020,1,6,18,30,20); 
dtDateTime.ToLongDateString = "Sunday, January 06, 2020" 

When the settings are UK the format is as follows:

dtDateTime.ToLongDateString = "January 06, 2002" 

ToShortDateString

This format does not always display correctly and will depend on local settings.

dtDateTime.ToShortDateString = 01/06/2002 

ToString

Again there are 2 different ways

Dim sDateString As String 
sDateString = Now().ToString("dd mmm yy") 
sDateString = System.DateTime.ToString(Now()) 

DateTimeFormatInfo

Defines how DateTime values are formatted and displayed
Added in .NET 2.0

Other Formats

dtDateTime.ToShortTimeString = 6:30 PM 
dtDateTime.ToLongTimeString = 6:30:20 PM 
dtDateTime.ToFileTime = 126548334205000000 
dtDateTime.ToOADate = 37262.7710706019 
dtDateTime.ToUniversalTime = 1/6/2002 11:30:20 PM 
dtDateTime.ToLocalTime = 1/6/2002 1:30:20 PM 

DateTime.ToString

When you want to format a date you have two choices.
(1) Use a built-in standard date format
(2) Use a custom date format

To format a date tou can use the ToString method

System.DateTime oDateTime; 
oDateTime = System.DateTime.UtcNow; 
System.Diagnostics.Debug.Print(oDateTime.ToString("dd-mm-yyyy")); 

Instead of always using a custom date format there are also some built-in standard formats
These standard formats are only one character long.
If the format provided has more than one character it is assumed to be a custom format.

System.Diagnostics.Debug.Print(oDateTime.ToString("d")); 

System.Diagnostics.Debug.Print(oDateTime.ToString("d", new CultureInfo.CurrentCulture)); 
System.Diagnostics.Debug.Print(oDateTime.ToString("d", new CultureInfo("en-US")); 
System.Diagnostics.Debug.Print(oDateTime.ToString("d", new CultureInfo("en-GB")); 

The easiest way to obtain a date/time in a a specific format is to use the ToString method

oDateTime.ToString("dddd, dd mmm yy") = "Monday, 18 Jul 06" 

oDateTime.ToString("m") = ?? 

You must use "MM" and not "mm" when converting a DateTime to a specific text format

oDataRow.Item("Birthday") = Me.dtpClientBirthday.Value.ToString("dd/MM/yyyy") 

String to DateTime
String to TimeSpan

System.String.Format

System.String.Format("Current Date is {0:f}", Now()) = "Current Date is Monday, February 08, 2006 4:28 PM" 

If you cannot find a standard date and time format that is appropriate you can create your own format putting together the special characters.

System.String.Format("Current Year is {0:yyyy}", Now()) = "Current Year is 2006" 

The / and : formatting characters are particularly elusive because they are replaced by the default date and time separator defined for the current locale.
When formatting dates for SQL SELECT statements you want to can make sure that the given separator is used on all occassions by using the backslash escape character to force a specific separator.

System.String.Format("{0:dd\/MM\/yyyy}", Now()) = "01/05/2006" 

System.DateTime.Now.ToString("hh:mm:ss") - this returns the current date and time 
System.DateTime.Now.ToString(ddd mmmm") - this returns the current date and time 

Date Formats

Time Formats