I find it peculiar how american companies think that no one is ever going to use their app outside of the US.
Usually this is just a minor annoyance or something to laugh at for us europeans, but on my first day in the office such mistake made some people think that I has left the office when I did not. Nothing came out of it and they have flexible hours so it was not going to be a problem even if I did not notice it, but it is pretty troubling that there is even the possibility of something like this happening. We are using slack (as most companies do nowadays) to talk with people in the office so we don’t have to necessarily walk up to them all the times and I’ve been offline for hours, while my mac was on.
Fortunately it already happened to someone else in the company so as soon as I asked they already knew the answer: Slack automatically sets everyone’s location and timezone in the desktop (and mobile?) app to California. On top of that it automatically set you as away during nighttime, even if your screen is on and without asking you. Unfortunately night time in California is daytime in Europe…
Why they’re not using the locale/timezone of the local machine is beyond me.