Stephens' Visual Basic® Programming 24-Hour Trainer

Chapter 15. Working with Dates and Times

One of Visual Basic's more confusing data types is Date. A Date represents a date, a time, or both. For example, a Date variable might represent Thursday April 1, 2011 at 9:15 a.m.

In this lesson, you learn how to work with dates and times. You learn how to create Date variables, find the current date and time, and calculate elapsed time.

Note

The DateTime data type is a synonym for Date.

CREATING DATE VARIABLES

You can initialize a Date variable to a literal value by surrounding it in number signs as shown here:

Dim dueDate As Date = #10/31/2011 1:23:00 PM#

You can also initialize a Date by using the New keyword as in the following code:

Dim dueDate As New Date(2011, 10, 31)

The preceding code uses a year, month, and day to initialize its Date variable, but the Date type lets you use many different kinds of values. The three most useful combinations of arguments specify the following (all as integers):

• Year, month, day

• Year, month, day, hour, minute, second

• Year, month, day, hour, minute, second, milliseconds

You can also add a kind parameter to the end of the second and third of these combinations to indicate whether the value represents local time or UTC time. (Local and UTC times are explained in the next section.) For example, the following code creates a Date representing 12 noon on March 15, 2010 in the local time zone:

Dim idesOfMarch As New Date(2010, 3, 15, 12, 0, 0, DateTimeKind.Local)

LOCAL AND UTC TIME

Windows has several different notions of ...