Timmy is a general-purpose time and calendar library for OCaml.
It supports advanced calendar features, enforces timezone safety, supports daylight saving times and overall focuses on the cleanliness, safety and completeness of its API.
Timmy's documentation can be found online.
Timmy is not yet released to opam and can be installed with a manual pin:
opam pin timmy 'git+https://github.com/mefyl/timmy#0.14.2'
opam install timmy