timezone

Time-zone handling
README

Timezone handles parsing timezone data and create [Timezone.t] that
can later be used to manipulate time in
core (using [Time] and [Time_ns]
modules).

Timezone is currently only able to read the Timezone Database
provided by IANA. It should work
out of the box on Linux and macOS.

Where are the timezone data located ?

The location of the timezone files can be set using the environment
variable TZDIR. If not set, [Timezone] will fallback to
/usr/share/zoneinfo/.

What is the local timezone ?

The local timezone can be set using the environment variable TZ. If
not set, [Timezone] will fallback to /etc/localtime.
In a JavaScript context, we automatically set the environment variable
TZ to Intl.DateTimeFormat().resolvedOptions().timeZone.

Compatibility with JavaScript.

The [Timezone] library can be used when constructing JavaScript
applications with
Js_of_ocaml.

Node.js

[Timezone] should work out of the box when running on a Node.js
environment on Linux or macOS. The file-system is accessible in that
case.

Web browsers

In a web browser environment, the [Timezone] library requires some
additional setup. One should generate a JavaScript file that will
embed all timezone data required by the application. This can be done
by using a tool provided by js_of_ocaml called jsoo_fs. The
generated JavaScript file will have to be included in the HTML page
before the JavaScript program itself.

For example, one can embed all timezones in all-tz.js with the following command:

grep -r TZif /usr/share/zoneinfo -l | xargs -n 1 -I {} echo {}:{} | xargs jsoo_fs -o all-tz.js

Example

open Core

let now = Time_ns.now ()

let () =
  Time_ns.to_sec_string now ~zone:(Lazy.force (Timezone.local))
  |> print_endline

let () =
  Time_ns.to_sec_string now ~zone:(Timezone.find_exn "America/New_York")
  |> print_endline

Please report bugs and feature requests on
GitHub.

You can find all of Jane Street's open-source libraries on
GitHub.

Documentation can be found
here.

Install
Sources
timezone-v0.15.0.tar.gz
sha256=a5fecedd06c779a7a6c0b910e2a1bfc7119049a57e8f6c59bf18752c1271410d
Dependencies
dune
>= "2.0.0"
ppx_jane
>= "v0.15" & < "v0.16"
core
>= "v0.15" & < "v0.16"
ocaml
>= "4.08.0"
Reverse Dependencies
core_unix
>= "v0.15.0"