elixirecto

How to convert timestamp to DateTime in Elixir?


How to convert the time in milliseconds to Ecto.DateTime?

The time in milliseconds is the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.


Solution

  • Here's one way to do this while preserving the millisecond accuracy:

    defmodule A do
      def timestamp_to_datetime(timestamp) do
        epoch = :calendar.datetime_to_gregorian_seconds({{1970, 1, 1}, {0, 0, 0}})
        datetime = :calendar.gregorian_seconds_to_datetime(epoch + div(timestamp, 1000))
        usec = rem(timestamp, 1000) * 1000
        %{Ecto.DateTime.from_erl(datetime) | usec: usec}
      end
    end
    

    Demo:

    IO.inspect A.timestamp_to_datetime(1466329342388)
    

    Output:

    #Ecto.DateTime<2016-06-19 09:42:22.388000>