I think that if you're taking a month-long break, you are effectively broken up and have permission to go smang somebody else because, you know, "WE WERE ON A BREAK!!!!!!"
Why would anybody want to take a break that long anyway? What purpose does it serve? You know pretty quickly if the relationship your getting some space from is something you don't want to be apart of. The entire purpose of a break is to do some major thinking about what you really want from the other person. It doesn't take a month to do that.
Further, what are you doing in that month? I think that if you think that you need a month "off" you might as well cut the chord and go frolick and play with some elves and dwarves and keep it moving. The only way I can see this month-long break working is if the two people intended to end the relationship, went off looking for something better (or thought they HAD something better) only to realize that maybe the decision to break things off was too hasty. At which point, they return together under a shower of angel wings and violin-choirs playing The Verve's "Bittersweet Symphony" in truly ironic fashion.
But in general, if you need a month off, you probably need two. And if you need two, you need to fully evaluate just what in the hell you're doing with this person anyway.
One month off = death knell.
It was written.
To my knowledge, "Months Off" generally means one of you is going out of town or will be out of touch for a month (backpacking through Europe with friends, going to see the family in India for a wedding, etc.), and you want the green light to get a little silly in their absence, guilt free.
And, If part of this stems from an insecurity about whether or not you're right for each other, you'll know waaaay before that month is over. I went to Israel on a group trip for 12 days last year, and I wondered how it would feel to be in a group full of strangers. Would I have a connection with someone (other than my boy at home)? Would that be a BAD thing? And, sure, there were really cool people, some of whom I was attracted to, but I missed my boyfriend the whole damn time.
Either way, breaks are for married couples who are separating and going through counseling. If you feel like you need a month-long break from a boyfriend, you probably have an answer.