+2024-03-09: I misunderstood how expect() works in rust. In a Result it won't return Err, it'll panic. .map_err() and ok_or_else() are a closer way to offer the same result.
2024-03-06: The definition of the first week in the ISO standard is the one that contains january 4th.
2024-03-06: In lua os.time() if you pass month 13 or month -1, it correctly calculates the next or previous year, so you don't have to manually do that math.
2024-03-03: The string methods in lua are attached to the metatable so you can run them with :, but the table ones aren't so you always need table.method().