There's a movie out touting the fun and problems of having a "hall pass" from your spouse or significant other. Would that be a good idea?
First, You'd have to decide when in your relationship is the best time to schedule something like this. Would it be at the end of year one, five, seven (year itch), ten, twenty? Then, how long is this "pass" good for? A day, a week? Are there rules? Who are you seeing/sleeping with during that time? An old fling, an old boyfriend/girlfriend, your spouse's best friend? What if you decide the grass is greener somewhere else? Yesterday you were perfectly content the way things were and now...
Why would you want a "hall pass"? Do you have an urge so strong you can't suppress it? Are you unhappy with things in your current relationship that a night on the town will cure? Are you cheating and feeling guilty and think if a "hall pass" is granted guilt will disappear? Not that old fashion cheating is ok, but this just sounds like an "open relationship". Why set a timeline? Just see who you want all the time. That would be easier and less strategy involved.
What if you enjoyed the "hall pass" so much you didn't want to go back to your old relationship? If you're looking for an excuse to end it, just man-up and end it. Why blame it on the "hall pass"? Are you hoping you'll find out the grass isn't greener and the romance will suddenly bounce back into your old relationship. Got some news for you, relationships take work. Sometimes they aren't pretty, fun or enjoyable, kind of like your job. Oh, it can be greener somewhere else but there'll be work there too. Nothing in life is free or easy.
Lastly, can you go back to your relationship after a "hall pass" and take up where you left off? Don't you think you'd both be different? Even with permission you cheated. Heck, they probably did too. Are you both ok with that? Were any feeling hurt with who you "hall passed" with? Have you learned to appreciate each other or resent each other? Is your relationship more complicated now knowing what you both think you're missing?
The biggest question is would you have been better off not knowing what you were missing? Maybe you should have taken that time to work on your relationship together instead. Hmmm...things to think about.