CDate and IsDate

[Guest]

Hi
The following test fails using CDate, can anyone explain why and how I can
produce the correct answer 'is not valid'? As it is, CDate evaluates the
invalid year 0000 to 2000 and results in an 'out of range' result incorrectly.

Input to 3 textboxes gives:
txtDay.Text = 12
txtMonth.Text = 05
txtYear.Text = 0000

tmpdate = CDate(txtDay.Text & "/" & txtMonth.Text & "/" & txtYear.Text)
If IsDate(tmpdate) = False Then
MsgBox "Please re-enter, " & txtSDay.Text & "/" & txtSMonth.Text & "/" &
txtSYear.Text & " is not valid. ")
Exit Sub
ElseIf tmpdate < DateAdd("yyyy", -1, Now()) Or tmpdate > Now() Then
MsgBox "Please re-enter, " & txtDay.Text & "/" & txtMonth.Text & "/" &
txtYear.Text & " is not within range. ")
End If

T.I.A

Geoff

 

[Bob Phillips]

Try

tmpdate = dateValue(txtDay.Text & "/" & txtMonth.Text & "/" & txtYear.Text)

 

[Guest]

Hi Bob
No, 0000 still evaluates to 2000.
Researching further, permitted dates go back as far as Jan 1 100AD so 0000
should fail when using IsDate.

Geoff

 

[Guest]

Further testing reveals:
From 01 Jan 0001 to 31 Dec 0029 the year is returned as 20xx
From 01 Jan 0030 to 31 Dec 0099 the year is returned as 19xx
From 01 Jan 0100 the year is returned correctly.

Both IsDate and CDate operate on the same basis.

Clearly I must test the year txtbox component separately for zero.

Geoff