There is no set timeframe to report harassment. If you are harassed you should report it right away if you want an accurate records of events. Memories tend to fade. Plus, the longer you wait the less likely the other side is to belive this was a big issue for you. Your response will be it was traumatic and eventually reached a breaking point, but better from a legal perspective to move sooner rather than later. There is a statute of limitations on a harassment lawsuit. Contact a lawyer right away if you have a case to pursue.