Have you ever needed a programmatic tool for determining whether the age difference between two people was too great to be socially acceptable, according to the half-plus-seven rule? Yeah, me neither, at least until I was playing a roleplaying game one night and the question of how young was too young came up for determining the appropriateness of a relationship between two fictional characters.
Because I have a tendency to like to automate tedious (but otherwise trivial) tasks just for the fun of it, I ended up writing a throw-away script for just that purpose. Because I tend to generalize the capabilities of throw-away scripts so they can be used to perform more tasks without significantly increasing the complexity of the script, I turned it into a fairly robust, while still very code-light, API for determining the appropriateness thresholds for age differences according to the half-plus seven rule. All told, this took about twenty minutes, roughly ten of which were spent figuring out how to turn "divide your age by two, then add seven years" into a more flexible formula (14 + Age Difference).
Because I am very bad at ignoring a hackish (if somewhat generalized) script, I then turned it into a Ruby library gem, complete with a small sample command line utility. I will encompass more of the API's capabilities in the command line utility "soon". I will then polish it up a bit, also "soon", and after that I'll publish it, another "soon" time later. The end result will be a programmatic toolset you can use for all your half-plus-seven compliance calculation needs, getting a definitive answer to the question of whether (prospective or actual) relationships are "creepy" -- a toolset whose very existence is, perhaps, ironically creepy itself.
This whole thing is kind of a silly joke that is getting way out of hand. If you are very seriously concerned about whether your dating choices meet the standards of the half-plus-seven formula, your priorities are probably a little screwed up, but I'm no psychologist. I leave it to you to straighten out the urges of your head, your heart, and your other sundry body parts.