For anyone who watches Doctor Who?

Well, now that is a good question. One of the many unanswered questions in that episode. I mean firstly, exactly when were the Doctor and Martha sent back to 1969? It was at least several years before Sally gives the Doctor her package at the end of the episode. Then exactly how long were the Doctor and Martha in 1969? Martha had to get a job. That takes time just to find a job in the first place. And she's been working the job for a while. Also the Doctor builds a timey-wimey detector. How long does it take to build a timey-wimey detector?? So many things left unanswered. So sorry I don't know the answer! I've put a star to your question. Maybe one of my contacts will have a theory.