Simple and efficient timestamp representation. The main objective being interoperability with OCaml Core_kernel.Time_ns.

A significant part of the code has been adapted from the OCaml Core_kernel implementation.

The set of supported timezones can be filtered using the TIMENS_TZ_FILTER environment variable, e.g.:

TIMENS_TZ_FILTER="London|New_York|Hong_Kong|Tokyo|GMT" cargo build

The tz repo is included as a git subtree, this can be updated via:

git subtree pull --prefix tz https://github.com/eggert/tz.git main --squash