Arch Linux distro is not the best of the Linux desktop 💻 and is a great example for Linux distribution in the Linux ecosystem and the desktop 💻 and its desktop is the most important part.

Clearly the FUTO keyboard has no idea about Arch

Thats an issue with the time library, not with timestamps. Actually timestamps are always in UTC, you need to do the conversion to your local time when displaying the value. There should be no possible off-by-one errors, unless you are doing something really wrong.

Kotlin without a doubt.

Gives you more flexibility and freedom that most scripting languages. The syntax is clean and concise, the tooling is amazing and can compile to JVM, JS, Native and WASM.