**A time machine malfunctions and spits a traveller from ~2015AD out in 500BC northern France. With nothing but the clothes on his back, and minimising contact with the locals (as that may risk altering timelines), how can he best determine his approximate location and time period?**

His pockets contains only coins, a wallet with both Canadian and US money and credit cards, keys, and a few dirty tissues. He's wearing business attire - black jacket, black shoes, tie, button up blue shirt, nice pants.

He knows a little bit of modern French (He can navigate a Quebec café menu), and a few touristy Spanish phrases, but not the languages that may have been spoken in this time period in this place. He doesn't know Celtic, or Greek, or Latin or Italian. He probably can't even recognise them if he hears them. His main language is Canadian English.

He's never been to France but has definitely read the odd relevant Wikipedia page.

He is in his 40s, and has few cuts and bruises from the time-mishap, but otherwise is in great physical condition. He's a star at his local gym where he can basically bench press the other customers. He's mentally sharp, ex-military, ex-police, basically [the guy from this related question about a tough smart guy making a time determination](https://worldbuilding.stackexchange.com/q/185746/78800) but a few years senior.

His time machine has previously only connected his 2 offices located at two different points in history, where he has separate past-and-present identities and has been slowly transferring knowledge back in time to accumulate wealth for himself through a series of lucky stock market plays and "insightful" patents. He has no idea why it malfunctioned and sent him to some random point in time on the other side of the globe.