Windows 10 also now has automatic timezone setting like MacOS. Since laptops generally don't have GPS chips on them, Apple, Microsoft, Google, et. al. have databases to map WIFI hotspots to location coordinates. Your laptop will query these databases with the WIFI MAC address to get it's location. Google got into some hot water a few years back by automatically populating their database by using their Streetview vehicles to map out WIFI hotspot locations. They now apparently use GPS equipped phones/tablets to populate their databases. There are almost certainly cases where these databases are incomplete or inaccurate. There are also probably fall back mechanisms -- DNS LOC records, whois queries for the address space, etc. which can have their own accuracy issues. I can't really find any good information on how Microsoft provides location services. I also just leave the automatic timezone setting turned off.

http://www.zdnet.com/article/how-goo...location-data/