tests are timezone and locale dependent (web)

[Pascal-So]

To anyone experiencing failed tests when running make test-web outside of a devcontainer, make sure you set the following environment variables:

LANG=en_US.UTF-8 TZ=UTC make test-web

Fun fact, I noticed that the time zone is only an issue east of Greenwich. The issue seems to be that a datetime in UTC is incorrectly interpreted as localtime and then converted back to UTC, which shifts any datetimes at midnight to the previous day if your offset to UTC is positive. Culprit right here if I'm not mistaken.

I'm aware that the devcontainer solves this issue, but I still think that devcontainers are a bit of a pain if you're not using VS Code (in my case helix) so I sometimes play around with everything outside the devcontainer 😄. Therefore I decided that this was not important enough to open an issue, but I still wanted to post the information here in case anyone else runs into this.