We have a field in our Time Entry layout that we use to track the actual date work was performed on a ticket in situations where the ticket record was updated after the actual work was done.  We would like to have a check each time the Time Entry is created, updated, etc... that verifies that the Date Worked field is <= the current date.  The validation rules are basic on the date field and don't have an option for "Today" or "Current Date" or anything like that.  Does anyone know how we could accomplish this?