Re: os.time() modifies the argument

[Egor Skriptunoff <egor.skriptunoff@...>]

the `isdst` field was forcibly overridden: it was
explicitly set to false, but the call to os.time ignored that and
changed it to true anyway.

"isdst" is not an independent parameter.

It could not be set to whatever user wants.

"isdst" is calculated based on the date and the location (your time zone).

This is similar to how "wday" is calculated as function of the date.