Module-level since we can't have static immutable associative arrays, and as
such populated in a module constructor.
The alternative is to put it in TimePlugin and have a module-level setup
that populates it, but since it never changes during the program's run time,
it may as well be here.
Timezone string aliases.
Module-level since we can't have static immutable associative arrays, and as such populated in a module constructor.
The alternative is to put it in TimePlugin and have a module-level setup that populates it, but since it never changes during the program's run time, it may as well be here.