How does Duolingo calculate your time zone?
According to the Help article What is my time zone set to?
Your time zone will be consistent with the time zone of the location where you created your account.
However, your time zone will change automatically whenever your device's timezone is updated (for example, when you travel). You may need to close and re-open your app, and confirm that your device's time zone has changed as well.
To locate the Help articles, visit https://support.duolingo.com/hc/en-us.
You can also locate the Help articles by hovering over your username where it appears in the blue bar at the top of the screen (desktop version). A menu will drop down. From the options, click "Help". Accessing this from an English base-language course will provide a fuller menu of articles for some reason.
Why would I want to know how Duolingo calculates time zones? There are a couple of reasons: such as your position on leader boards if you are in competitions and if you are interested in preserving your Streak. (However, there are other considerations for preserving your streak as well. I've outlined the things you'll want to be aware of in the discussion Checked your streak freeze today?)
[Under construction] Once I figure out how the leader board in the Club feature works with multiple time zones, I'll add that bit of info. :)
It was reported many times. For almost 3 years that I have been here, I do not remember that the duolingo's midnight coincided with my local midnight. I live in Moscow time, and that happens not only for me. This post was written 3 years ago and has 70 comments (Russian): What a pity that the day shift at Duolingo at 22:00(((. This problem is still relevant.
Actually, I do not remember that they reacted to at least one of my error reports. All this is very sad :(
Maybe they are aware but it is a bigger fix than they could prioritize. I'm just talking out of my tail though, because I don't know.
I'll go ahead and send a new bug report since y'all have already used your time to do it in the past. I hope eventually they are able to fix it. Sounds frustrating.
My guess is the lingotpocalypse glitch. People would go to donate a couple of lingots to someone, and a glitch would dump hundreds if not thousands of lingots on that person. It didn't happen consistently. But, for a week or two it was happening frequently enough. I got around 1,000 that way.