Way to add in Week #s for individual dates within a program

To make it apparent to members and staff what week we are on within a program session, it would be very helpful if there were a way to add a Custom Field to individual dates within a program. For example, our clinics run for 4 weeks. We would like to add "Week 1" to the first date, "Week 2" to the second date, and so on. That way, anyone could see what week we are on without having to look back at the dates and count. We do not allow full registrations, only individual. If someone wants to register for a full session, they just have to click each date.