WhereTZ is elixir version of Ruby gem for lookup of timezone by georgraphic coordinates.
https://github.com/zverok/wheretz
Features:
- no calls to external services, works without Internet connection;
- Timezone result is %Timex.TimezoneInfo
Add to project from hex.pm
def deps do
[
{:wheretz, "~> 0.1.17"},
]
end
or from github
def deps do
[
{:wheretz, git: "git@github.com:UA3MQJ/wheretz.git", tag: "v0.1.17"},
]
end
Before the first start, you need to download the geo and initializse the database.
mix where_tz.init
usage
iex(1)> WhereTZ.get(50.004444, 36.231389)
#<TimezoneInfo(Europe/Kiev - EET (+02:00:00))>
iex(2)> WhereTZ.lookup(50.004444, 36.231389)
"Europe/Kiev"
- Latest version of timezone-boundary-builder dataset is converted into mnesia table (125Mb);
- For each time zone, store timezone name, geo polygon and calculate bounding box (min and max latitude and longitude);
- On each lookup
WhereTZ
first checks provided coordinates by bounding boxes, and if only one bbox, corresponds to them, returns timezone name immediately; - If there's several intersecting bounding boxes,
WhereTZ
checks which polygon actually contains the point.
- ?
Alexey Bolshakov
Data license is ODbL.
Code license is usual MIT.