This is loosely based on tyskland's idea [link]
If you were to have three revolving doors inset into each other, a small maze on the way into work would ensue.
By using 3 of the 2 door revolving doors, and setting each one to be set on a wider axis than the previous, they could rotate based
on time and have a constantly moving appearance.
The outermost door could rotate once every 12 hours, the middle door every hour and the innermost door could complete one rotation every minute.
See pic for a (slightly) clearer representation.
Sure, if you got to work at exactly the same time everyday, it would be a little boring... but how many people get to work on the same second every day?