Date/Time recognition

[Gord]

Hello,

VB6 accepts Date and Time values as 'Date'. I'm trying to verify entry into
a database I'm creating by verifying that an appropriate Date or Time value
has been entered. Using built-in VB functions/properties etc., I can't seem
to unambiguously confirm that an entry is a valid date or valid time value?
(I would like to try and do this without having to write some huge procedure
that processes an entry character by character, especialy with all the
permutations that are possible) 'IsDate' recognizes date or time as 'Date',
and I can't seem to interogate the variables to confirm it's one or the
other. I've been playing around with 'DateValue', 'DatePart', 'TimeValue',
'Year' functions etc............Ahhhhhh.

A suggestion in the right direction would be appreciated.

Thanks,

Gord

[Rick Rothstein]

> VB6 accepts Date and Time values as 'Date'. I'm trying to verify
entry into

a database I'm creating by verifying that an appropriate Date or Time value has been entered. Using built-in VB functions/properties etc., I can't seem to unambiguously confirm that an entry is a valid date or valid time value? (I would like to try and do this without having to write some huge procedure that processes an entry character by character, especialy with all the
permutations that are possible) 'IsDate' recognizes date or time as 'Date', and I can't seem to interogate the variables to confirm it's one or the other. I've been playing around with 'DateValue', 'DatePart', 'TimeValue', 'Year' functions etc............Ahhhhhh.

A suggestion in the right direction would be appreciated.

It is not completely clear to me whether you are trying to verify that
the entries are in the correct format for Dates and Times or simply if
the entry is a Time entry or a Date entry. I kind of think you are
looking for the latter. If so, you should be able to use these two
statements (don't change the colon or slash, using them makes the Format
statement return the value that is specified in the Regional settings,
whatever it is)...

DateSeparator = Format$(0, "/")
TimeSeparator = Format$(0, ":")

coupled with the InStr function to determine if the entry (assuming it
is properly formatted) is a Date entry, a Time entry or neither.

If InStr(YourEntry, DateSeparator) Then
MsgBox "Your entry is a Date."
ElseIf InStr(YourEntry, TimeSeparator) Then
MsgBox "Your entry is a Time."
Else
MsgBox "Your entry is neither!"
End If

Rick - MVP

[Raoul Watson]

"Gord" <x1******@telus.net> wrote in message
news:1cHwc.24878$jl6.7297@edtnps89...

Hello,

VB6 accepts Date and Time values as 'Date'. I'm trying to verify entry into a database I'm creating by verifying that an appropriate Date or Time value has been entered. Using built-in VB functions/properties etc., I can't seem to unambiguously confirm that an entry is a valid date or valid time value? (I would like to try and do this without having to write some huge procedure that processes an entry character by character, especialy with all the
permutations that are possible) 'IsDate' recognizes date or time as 'Date', and I can't seem to interogate the variables to confirm it's one or the
other. I've been playing around with 'DateValue', 'DatePart', 'TimeValue', 'Year' functions etc............Ahhhhhh.

A suggestion in the right direction would be appreciated.

Thanks,

Gord

You should be able to use the "IsDate" function to check both time and date.
For example:
? isdate("25:78")
False
? isdate("11:50am")
True
? isDate("4/5/04")
True
? isdate ("2/31/04")
False

I believe Rick addressed how to check the separator to see if it is a time
entry.

[Gord]

Rick,

Thanks. You're right, I am trying to determine if an entry is a date or
time. Formatting comes later. Your solution works, although it seems to be
necessary to copy the entry into a 'Date' variable in order for the 'InStr'
function to work. Even if 'IsDate' says a textbox entry is a valid date,
using that textbox (or a string variable) in the 'InStr' function won't
work. In your example 'YourEntry' needs to be a date variable.

I'm using the Microsoft reference library and Programmers Guide to (attempt)
to teach myself some basic programming. I'm wondering what the 'Format$(0,
"/")' or 'Format$(0, ":")' is all about? What expression does the '0'
represent?

Thanks

Gord
"Rick Rothstein" <ri************@NOSPAMcomcast.net> wrote in message
news:Ee********************@comcast.com...

VB6 accepts Date and Time values as 'Date'. I'm trying to verify

entry into

a database I'm creating by verifying that an appropriate Date or Time

value

has been entered. Using built-in VB functions/properties etc., I

can't seem

to unambiguously confirm that an entry is a valid date or valid time

value?

(I would like to try and do this without having to write some huge

procedure

that processes an entry character by character, especialy with all the
permutations that are possible) 'IsDate' recognizes date or time as

'Date',

and I can't seem to interogate the variables to confirm it's one or

the

other. I've been playing around with 'DateValue', 'DatePart',

'TimeValue',

'Year' functions etc............Ahhhhhh.

A suggestion in the right direction would be appreciated.

It is not completely clear to me whether you are trying to verify that
the entries are in the correct format for Dates and Times or simply if
the entry is a Time entry or a Date entry. I kind of think you are
looking for the latter. If so, you should be able to use these two
statements (don't change the colon or slash, using them makes the Format
statement return the value that is specified in the Regional settings,
whatever it is)...

DateSeparator = Format$(0, "/")
TimeSeparator = Format$(0, ":")

coupled with the InStr function to determine if the entry (assuming it
is properly formatted) is a Date entry, a Time entry or neither.

If InStr(YourEntry, DateSeparator) Then
MsgBox "Your entry is a Date."
ElseIf InStr(YourEntry, TimeSeparator) Then
MsgBox "Your entry is a Time."
Else
MsgBox "Your entry is neither!"
End If

Rick - MVP

[Steve Gerrard]

"Gord" <x1******@telus.net> wrote in message
news:tZryc.28778$%i1.24850@edtnps89...

Rick,

Thanks. You're right, I am trying to determine if an entry is a date or time. Formatting comes later. Your solution works, although it seems to be necessary to copy the entry into a 'Date' variable in order for the 'InStr' function to work. Even if 'IsDate' says a textbox entry is a valid date, using that textbox (or a string variable) in the 'InStr' function won't work. In your example 'YourEntry' needs to be a date variable.

Like IsNumeric(X), which answers the question, "can I call CDbl(X)
without getting an error?", IsDate(X) answers the question "can I call
CDate(X) without getting an error?" Rick can post for you a fine example
of why IsNumeric is otherwise useless for checking for valid numeric
input.

I would do this something like:
Dim dtTest As Date

If IsDate(Text1.Text) Then
dtTest = CDate(Text1.Text)
If dtTest > 0 And dtTest < 1 Then
Debug.Print "its just a time"
ElseIf dtTest >= 1 And Fix(dtTest) = dtTest Then
Debug.Print "its just a date"
ElseIf dtTest >= 1 Then
Debug.Print "its a date and time"
End If
End If