Lead Validation Rule is not working

Question

I am trying to create a validation rule so that if a date/time field on a lead is either blank or in the past And if the lead status picklist field equals "Appointment Set" then a validation rule error would appear.

When I save a record with the lead status of "Appointment Set" and leave the Appointment Date field blank the system lets me save a record without any error message appearing.

Here is what my validation rule formula looks like

    (Appointment_Date__c   <   NOW() || ISBLANK( Appointment_Date__c ))  &&  

    (ISPICKVAL( Status , "Appointment Set"))

Answer 1

NOW() function gives you Datetime. So it's not appropriate to compare it with date field. Try using this formula:

AND(
    OR (Appointment_Date__c   <   NOW(), 
        ISBLANK( Appointment_Date__c )), 
    (ISPICKVAL( Status , "Appointment Set"))
    )

Answer 2

I see what the problem is. I had an underscore in the api name for the Appointment Set value in the lead status field. That is why the validation rule was not recognizing it. Thanks for everyone trying to help.