Time zone using tzdata

Mix.install([
  {:tzdata, "~> 1.1"}
])

# By default TZ database is Calendar.UTCOnlyTimeZoneDatabase
Calendar.UTCOnlyTimeZoneDatabase = Application.get_env(:elixir, :time_zone_database)

# Replace it with Tzdata.TimeZoneDatabase
Application.put_env(:elixir, :time_zone_database, Tzdata.TimeZoneDatabase)

Resources

• https://hexdocs.pm/tzdata/readme.html
• https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Time now in different time zones

DateTime.utc_now()

DateTime.now!("Asia/Tokyo")

DateTime.now!("America/New_York")

# explicitly with TZ database
DateTime.now("Europe/Copenhagen", Tzdata.TimeZoneDatabase)

now = DateTime.now!("Asia/Tokyo")
oshogatsu = DateTime.new!(~D[2023-01-01], ~T[01:01:00], "Asia/Tokyo")
awesome = oshogatsu

DateTime.diff(awesome, now, :hour)