Our protagonist is a completely normal 25-year old who just went on a walk through the city.
What he doesn't know: The morally dubious scientists of Evil, Inc. have decided that he is the perfect test subject for their experiment: Sending someone back in time.
The question now is: how far back can they send him, without people in the targeted time getting suspicious about our protagonist because of differences in culture, appearance, clothing, etc?
- The test subject has to survive two weeks on his own, without being suspected of being a criminal, strange, a time traveller etc. E.g. the police arrest him, the experiment has failed.
- The test subject has only the resources he has with him (portmonee, smartphone, his keys, clothing, some smaller snacks) and the resources he can obtain in the past.
He is told that he has under all circumstances to avoid being arrested, otherwise he will not be brought back! His top goal is to survive these two weeks, and be brought back. So, to reach that goal, he has to obtain food and shelter, not more, not less. I would assume that since he is clever, he would lie low for the time being.
Assume that the method of time travel is not damaging him and that the location he is popping up in the past is un-observed.
Edit to further narrow down the question: He is told to what time he will be transported. He is told under what ramifications he will be brought back. These ramifications are pretty simple: don't get killed, don't get arrested, don't get too much attention from the police/secret service/etc.
To respond to @Raditz's comment: The reason why the experiment is done is not important. That was the reason why I named them Evil, Inc. Maybe they are doing it for the Evulz (Attention: TVTropes-Link, abandon all hope)