It's all ethics so there is no correct answer regarding time limits or even dating patients at all.
It's not that it's forbidden by some law (unless you are in some hospital system that dictates this as part of its rules), it's that it is unethical and leads to possible trouble. We all know (well, except for some recluses) that relationships are fickle and can have a tendency to become vindictive and angry fiascos. Could you imagine your ex-girl/boy-friend suing you because of alleged mishandling of their medical concerns, just because you decided to move on to another relationship or city or whatever reason? You would be subject to massive monetary loss and, most likely, lose your liscense because no jury is going to have sympathy on you. You took advantage of the situation because you were in a position of power.
That said, general feeling is don't date patients or even relatives of patients. Our assistant dean has talked to us about this since day one, and his opinion is:
1) Don't do it.
2) If you simply cannot live without one another (which you must learn from a very brief meeting since you should not be dating), sever your relationship with the patient and any family and friends of this patient.
3) Remain out of contact (ANY contact- physical, verbal, etc.) for at least two years and preferably five years.
4) Even with all that, it may not hold up in a legal battle, but you have a better chance because it showed restraint and no attempt to use your position of authority.
