Strings.FormatDateTime Method (DateTime, DateFormat)

.NET Framework (current version)

Note
The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Returns a string expression representing a date/time value.

Namespace: Microsoft.VisualBasic
Assembly: Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

Syntax

C++

public static string FormatDateTime(
	DateTime Expression,
	DateFormat NamedFormat = DateFormat.GeneralDate
)

Parameters

Expression: Type: System.DateTime
Required. Date expression to be formatted.

NamedFormat: Type: Microsoft.VisualBasic.DateFormat
Optional. Numeric value that indicates the date/time format used. If omitted, DateFormat.GeneralDate is used.

Return Value

Type: System.String

Returns a string expression representing a date/time value.

Exceptions

Exception	Condition
ArgumentException	NamedFormat setting is not valid.

The Date data type always contains both date and time information. For purposes of type conversion, Visual Basic considers 1/1/1 (January 1 of the year 1) to be a neutral value for the date, and 00:00:00 (midnight) to be a neutral value for the time. If you format a Date value as a date/time string, FormatDateTime does not include neutral values in the resulting string. For example, if you convert #1/1/0001 9:30:00# to a string, the result is "9:30:00 AM"; the date information is suppressed. However, the date information is still present in the original Date value and can be recovered with functions such as DatePart.

Note
If you pass the Expression argument as a String literal, FormatDateTime interprets it according to the CurrentCulture setting of your application. However, if you pass it as a Date literal, use the format #mm/dd/yyyy#, because FormatDateTime always interprets a Date literal according to the English (US) culture. This is necessary because, if an application is developed and coded using Date literals from one culture, but is then executed on a platform with a different culture, the Date literals could be parsed incorrectly.

Note

If you pass the Expression argument as a String literal, FormatDateTime interprets it according to the CurrentCulture setting of your application. However, if you pass it as a Date literal, use the format #mm/dd/yyyy#, because FormatDateTime always interprets a Date literal according to the English (US) culture. This is necessary because, if an application is developed and coded using Date literals from one culture, but is then executed on a platform with a different culture, the Date literals could be parsed incorrectly.

The NamedFormat argument has the following settings.

Constant	Description
DateFormat.GeneralDate	Display a date and/or time. Display a date part as a short date. If there is a time part, display it as a long time. If present, both parts display.
DateFormat.LongDate	Display a date using the long date format specified in your computer's regional settings.
DateFormat.ShortDate	Display a date using the short date format specified in your computer's regional settings.
DateFormat.LongTime	Display a time using the time format specified in your computer's regional settings.
DateFormat.ShortTime	Display a time using the 24-hour format (hh:mm).

Examples

This example demonstrates the use of the FormatDateTime function.

' English (US) format.
Dim TestDate As DateTime = #3/12/1999#

' FormatDateTime returns "Friday, March 12, 1999".
' The time information is neutral (00:00:00) and therefore suppressed.
Dim TestString As String = FormatDateTime(TestDate, DateFormat.LongDate)

Version Information

.NET Framework
Available since 1.1
Silverlight
Available since 2.0