Let's try a little different approach......
Forget tee times. At my course, the days we maximize play is when we do two full-field shot guns back to back. The shot-gun idea just puts aside this arguement of how much time is the right amount of time between tee times. It is logistically fair to say a course is "full" when there are 2 groups on each par 4 (tee & fairway), 1 group on each par 3 (tee), and 3 groups on each par 5 (tee, fairway & approach/green), which usually amounts to 2 groups per hole on 18 holes. As such, a speedy pace of golf is still reasonable. Any more full and people are waiting all over and the pace of play goes way down.
Here's the math, tricked up with the comments people have made:
Assume they can tee off starting at 6am, on average, year round. Assume it is a short course and they can complete an 18-hole round in 4 hours (not unreasonable for a course of 5000 some odd yards). Assume they do 3 full-course, full-field (that means 2 groups per hole) shot-guns everyday at 6am, 10am and 2pm, which means the last group would finish by 6pm, which still leaves plenty of time. Assume every group is a 5-some.
So.....1 shot gun= 18 holes x 2 groups x 5 people/group =180 rounds
3 shot guns/day = 540 rounds
364 days/year = 196,560 rounds
Still gives maintenance 12 hours to do what they need to do (obviously would need headlights on everything) and the math still leaves room for groups less than 5, some inclement weather, and/or finishing later than 6pm.
Conclusion: It's POSSIBLE......but highly, HIGHLY unlikely that any golf course could pull this off day in day out. Even the logistics of us doing 144 + 144 (two full field shotguns in the same day) is INSANE. I give them credit for pushing alot of people through, but still believe there is some padding to those numbers.