Formatting dates with VB.NET and ASP.NET

This tutorial covers formatting dates. To follow this tutorial, there are some basic requirements:

A text editor or a visual web design program with HTML editing capabilities installed on your computer since this exercise will require hand coding. Examples include Notepad, Homesite, or Visual Studio.Net
Access to a server that has the Dot Net Framework installed. This is necessary to see the results of the formatting. If you are planning on using your local machine as a test server, you must use Windows 2000 (any version) or Windows XP Pro as your OS. The Dot Net Framework can be downloaded from http://msdn.microsoft.com/netframework/prodinfo/getdotnet.asp
A basic familiarity with VBNET and ASPNET is recommended. To get up to speed on ASPNET, there are some excellent articles at www.4guysfromrolla.com

Standard Format Specifiers for Dates and Times:

The table below shows the standard date and time formatters.

Format	Description	Example
d	Short Date
D	Long date
f	long date & short time
F	long date and long time
g	short date and short time
G	short date and long time
M or m	month and day
Y or y	year and month
t	short time
T	long time
s	displays in ISO 8601 format using local time
u	displays in ISO 8601 format using universal time
U	date and time in unversal time
R or r	displays in RFC 1123 format

Custom formatting sequences:

There are also specific character sequences that can be used to achieve custom formatting of dates and times.

Format	Description
d	day of month (1 or 2 digits as required)
dd	day of month (always 2 digits, with a leading 0 if needed)
ddd	day of week (3 letter abbreviation)
dddd	day of week (full name)
M	month number (1 or 2 digits as required)
MM	month number (always 2 digits, with a leading 0 if needed)
MMM	month name (3 letter abbreviation)
MMMM	month name (full name)
y	year ( last 1 or 2 digits, no leading 0)
yy	year (last 2 digits)
yyyy	year (4 digits)
H	hour in 24-hour format (1 or 2 digits as required)
HH	hour in 24-hour format (always 2 digits, with a leading 0 if needed)
h	hour in 12-hour format (1 or 2 digits as required)
hh	hour in 12 hour format
m	minutes (1 or 2 digits as required)
mm	minutes (always 2 digits, with a leading 0 if needed)
s	seconds (1 or 2 digits as required)
ss	seconds
t	first character in the am/pm designator
tt	am/pm designator
z	time zone offset, hour only (1 or 2 digits as required)
zz	time zone offset, hour only (always 2 digits, with a leading 0 if needed)
zzz	time zone offset, hour and minute
/	default date separator
:	default time separator
\	escape characters

Using the format specifiers:

Create a new aspnet page and add the <asp:label> control to the page. Assign an id to the control and set runat="server". Your page should resemble the following:

<%@ Page Language="vb" %>
<html>
  <head>
     <title>Formatting Dates</title>
  </head>
     <body>
        <asp:label runat="server" id="TheDateTime" />
     </body>
</html>

The next step is to write the subroutine that will display and format the date and time. Add the following code to the aspnet page just after the closing title tag.

Save the page and preview. The date should resemble the format 9/8/2002. Compare your result to the date on this page

This subroutine sets the Text property of the label control equal to the current date and time. Then by specifying "d" as the formatter, only the date portion is returned. Change the "d" to one of the other formatters to see how it affects the date and time that are displayed. For example, change the "d" to "g". You should now see something that resembles 9/10/2002 5:19 PM

Using the custom formatters:

Now its time to try out the custom formatting sequences. Lets say you want to display the date in the format 9-10-02. Using the custom formatters, it is very easy to to do so. Modify the subroutine you wrote earlier as follows:

Note that today's date is being formatted using the sequence "MM\-dd\-yy". Save the page and preview. The date should resemble the format 09-10-02.

In the format sequence, MM provides the month, dd gives the day of the month, and yy gives the last 2 digits of the year. The escape character \ must be used if the separator is to be the dash or any other nonstandard separator. Remember that the : and / are the standard separators for time and date respectively.