Name
IsDate Function
Class
Microsoft.VisualBasic.Information
Syntax
IsDate(expression
)
-
expression
Use: Required
Data Type: Any
Expression containing a date or time
Return Value
Boolean indicating whether the expression can be converted to a Date
Description
Determines if an expression is of type Date or can be converted to type Date
Rules at a Glance
Returns
True
if and only ifexpression
is of type Date or can be converted to type Date.Uninitialized date variables also return
True
.
Programming Tips and Gotchas
IsDate
uses the locale settings of the current Windows system to determine if the value held within the variable is recognizable as a date. Therefore, what is a legal date format on one machine may fail on another.IsDate
is particularly useful for validating data input. However, don’t useIsDate
in the VB text box control’s Change event. The Change event is fired with every keystroke, which means that when the user starts to enter the date, chances are that the date will be invalid until the point at which the user has completed the data entry.
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