When I wanted to make a change to my iCloud settings last night, I noticed that Find My Mac had a problem. The problem was location services was turned off, so I turned it on and went back to iCloud settings. However that annoying exclamation mark is still there.
Then I went to Security & Privacy panel and enabled it again and checked if it's reset when I left. The result is positive. Whenever I left this panel it's reset. That means there was something broken with my MacBook Air. Its mother board was just replaced and I don't want to visit Apple Store again. I wished it's just software
I googled it and found the answer. It's not the time zone. It's the iOS Simulator. I was experimenting something with jQuery Mobile and thus running iOS Simulator.
So does it mean if you lost your Mac when iOS Simulator is running you are not going to get it back by using Find My Mac? No. The location services toggle just appears to be off but no change actually happens to your Mac. I guess iOS Simulator's fake location just affects Mac's system level settings.