MS-Access query to only run once a day when first user opens.

one way to do this, which i have done in one of my application is to create a table with a Date/time field.

when the db is open, check if there is value in the Date field equal to the current date,
if no date found, run the query, then insert or update the date field with the current date.

got the idea?

I created a table called DateCheck with a field called ForDateCheck as a DateTime datatype.

So here is the code that I have written.  Please feel free to make any changes that you feel are syntacticly incorrect. Thanks.

Public Sub Check_Date()
If [DateCheck]![ForDateCheck] <> Now() Then
DoCmd.RunQuery "Qry_RunTestData"
Else
DoCmd.RunQuery "Qry_UpdateCheck_DateWithTodaysDate"
End If
End Sub

Can I run this code from a Macro in Access or do I need to change the code to a function.

* you can call the sub  in the open event of the form
* you can place the codes in the open event of the form
* you can change the Sub to a Function and run the Function from a macro

take your pick

I changed the code to a Function.  When I run the function from a Macro  I get the following Error:
RunTime error '2001':
You Cancelled the Previous Operation
    End         Debug

I choose Debug
and the first line of code is highlighted in yellow:

If Nz(DLookup("ForDateCheck", "DateCheck")) <> Date Then


By the way what is "Nz"?  Thanks.

Any ideas why this is happening?

Waiting for reply.

Ceck this database implementing my comment.
Code can be used in form open event or in a butto click event.
runQueryOncePerDay.accdb

Thanks.