IsDate Function

Purpose

Returns a Boolean value indicating whether an argument contains a Date type.

Syntax

Bool = IsDate(exp)

exp

: Variant, Date, or String expression

Description

IsDate returns True if the expression is a date or is recognizable as a valid date; otherwise, it returns False. In Microsoft Windows, the range of valid dates is January 1, 100 A.D. through December 31, 9999 A.D.; the ranges vary among operating systems.

NOTE: IsDate recognises dates without the year value and assumes that the year is the current year (e.g. 12/12 as 12th December of this year).

Examples

Local z As Date = HmsToTime(110000, 20, 4000)

Print IsDate(z) // True

Print IsDate(#16.12.1912#) // True

Local b$ = "31/12/2000"

Print IsDate(b$) // -1 -> True

Local c As Variant = "23/25/1943"

Print IsDate(c) // 0 -> False

Print IsDate("12/12") // -1 -> True (IsDate recognises this as day and month of current year)

...and...

Dim SomeDate, daysleft

Ocx Label lbl = "Enter Date:", 10, 10, 60, 14 : lbl.BackColor = RGB(255, 255, 255)

Ocx TextBox Text1 = "", 70, 9, 100, 14 : .BorderStyle = 1

Ocx Command cmd = "Calculate", 175, 7, 70, 18

Ocx Label Text2 = "", 10, 30, 200, 14 : Text2.BackColor = RGB(255, 255, 255)

Do : Sleep : Until Me Is Nothing

Sub cmd_Click

If IsDate(Text1.Text) Then

SomeDate = CDate(Text1.Text)

daysleft = Int(DateSerial((Year(SomeDate) + 1, 1, 1,)) - SomeDate)

Text2.Text = daysleft & " days left in the year."

Else

MsgBox Text1.Text & " is not a valid date."

End If

EndSub

Sub Text1_KeyPress(Ascii&)