View Source NervesTimeZones (nerves_time_zones v0.3.5)
Local time support for Nerves devices
The nerves_time_zones application provides support for local time on Nerves
devices. It does this by bundling a time zone database that's compatible with
the zoneinfo library and providing logic to set the local time zone with
the C runtime (and hence Erlang and Elixir).
To use, call NervesTimeZones.set_time_zone/1 with the any IANA time zone
name (e.g., "America/New_York"). The time zone will be persisted so you
won't need to set it again. It is safe to always set it on boot if your
project will always be located in one time zone.
After this, calls to NaiveDateTime.local_now/1 will return the local time.
If you would prefer DateTime struct, call
DateTime.now(NervesTimeZones.get_time_zone()).
If running a non-BEAM program that is time zone aware, you may need to set
environment variables for it to work right. See
NervesTimeZones.tz_environment/0 for the proper settings.
Summary
Functions
Return the current local time zone
Reset the time zone to the default
Set the local time zone
Return all known time zones
Return environment variables for running OS processes
Return whether a time zone is valid
Functions
@spec get_time_zone() :: String.t()
Return the current local time zone
@spec reset_time_zone() :: :ok
Reset the time zone to the default
This cleans up any saved time zone information and reapplies the defaults.
The default time zone is "Etc/UTC", but this can be changed by adding
something like the following to your config.exs:
config :nerves_time_zones, default_time_zone: "Asia/Tokyo"Set the local time zone
Only known time zone names can be set. Others will return an error.
"Etc/UTC" should always be available.
This time zone will be persisted and restored after a reboot.
@spec time_zones() :: [String.t()]
Return all known time zones
This function scans the time zone database each time it's called. It's
not slow, but if you just need to verify whether a time zone exists,
call valid_time_zone?/1 instead.
Return environment variables for running OS processes
If you're using System.cmd/3 to start an OS process that is time zone
aware, call this to set the environment appropriately. For example,
System.cmd("my_program", [], env: NervesTimeZones.tz_environment())
Return whether a time zone is valid