October 19, 2009

Date and Time Functions in Visual Basic 6

Not only does Visual Basic let you store date and time information in the specific Date data type, it also provides a lot of date- and time-related functions. These functions are very important in all business applications and deserve an in-depth look. Date and Time are internally stored as numbers in Visual Basic. The decimal points represents the time between 0:00:00 and 23:59:59 hours inclusive.

The system's current date and time can be retrieved using the Now, Date and Time functions in Visual Basic. The Now function retrieves the date and time, while Date function retrieves only date and Time function retrieves only the time.

To display both the date and time together a message box is displayed use the statement given below.

MsgBox "The current date and time of the system is" & Now

Here & is used as a concatenation operator to concentrate the string and the Now function. Selective portions of the date and time value can be extracted using the below listed functions.

Function
Extracted Portion
Year ( ) Year (Now)
Month ( ) Month (Now)
Day ( ) Day (Now)
WeekDay ( ) WeekDay (Now)
Hour ( ) Hour (Now)
Minute ( ) Minute (Now)
Second ( ) Second (Now)

The calculation and conversion functions related to date and time functions are listed below.

Function
Description
DateAdd ( ) Returns a date to which a specific interval has been added
DateDiff ( ) Returns a Long data type value specifying the interval between the two values
DatePart ( ) Returns an Integer containing the specified part of a given date
DateValue ( ) Converts a string to a Date
TimeValue ( ) Converts a string to a time
DateSerial ( ) Returns a date for specified year, month and day

DateDiff Function

The DateDiff function returns the intervals between two dates in terms of years, months or days. The syntax for this is given below.

DateDiff (interval, date1, date2[, firstdayofweek[, firstweekofyear]])

Format Function

The format function accepts a numeric value and converts it to a string in the format specified by the format argument. The syntax for this is given below.

Format (expression[, format[, firstdayofweek[, firstweekofyear]]])

The Format function syntax has these parts:

Part
Description
Expression Required any valid expression
format Optional. A valid named or user-defined format expression.
firstdayofweek Optional. A contant that specifies the first day of the week.
firstweekofyear Optional. A contant that specifies the first week of the year

No comments:

Post a Comment

Comment will be published after moderation only. Do not advertise here.