logicalType: date about avrora HOT 5 OPEN

defmodule Enc do
  # int logical types:
  def date(d) when is_struct(d, Date) do # int
   Date.diff(d, ~D[1970-01-01])
  end
  def date(d) when is_binary(d) and 10 == byte_size(d) do
    date(Date.from_iso8601!(d)) # this can obviously fail
  end

  # long logical types:
  def timestamp_millis(ts) when is_struct(ts, DateTime) do
    DateTime.to_unix(ts, :millisecond)
  end
  def timestamp_millis(ts) when is_binary(ts) do
    {:ok, utc, _tzsec} = DateTime.from_iso8601(ts)
    timestamp_millis(utc)
  end
  def timestamp_micros(ts) when is_struct(ts, DateTime) do
    DateTime.to_unix(ts, :microsecond)
  end
  def timestamp_micros(ts) when is_binary(ts) do
    {:ok, utc, _tzsec} = DateTime.from_iso8601(ts)
    timestamp_micros(utc)
  end
  def time_millis(t) when is_struct(t, Time) do
      {s,u} = t |> Time.to_seconds_after_midnight()
      s * 1000 +  Integer.floor_div(u, 1000)
  end
  def time_millis(t) when is_binary(t) do
    time_millis(Time.from_iso8601!(t))
  end
  def time_micros(t) when is_struct(t, Time) do
      {s,u} = t |> Time.to_seconds_after_midnight()
      s * 1000_000 +  u
  end
  def time_micros(t) when is_binary(t) do
    time_micros(Time.from_iso8601!(t))
  end
end

defmodule Dec do
  def date(int) do Date.add(~D[1970-01-01], int) end
  def timestamp_millis(long) do DateTime.from_unix!(long, :millisecond) end
  def timestamp_micros(long) do DateTime.from_unix!(long, :microsecond) end
  def time_millis(long) do
    seconds = Integer.floor_div(long, 1000)
    millisecs = (long - seconds * 1000) * 1000
    Time.from_seconds_after_midnight(seconds, {millisecs, 3})
  end
  def time_micros(long) do
    seconds = Integer.floor_div(long, 1000_000)
    microsecs = long - seconds * 1000_000
    Time.from_seconds_after_midnight(seconds, {microsecs, 6})
  end
end

ts_iso = "2019-10-12T17:57:42.123456Z"
ts_iso_tz = "2019-10-12T17:57:42.123456+0130" # 90 min before
ts_sig = ~U[2019-10-12 17:57:42.123456Z]
ts_sig_tz = ~U[2019-10-12 16:27:42.123456Z]
date_iso = "2019-10-12"
date_sig = ~D[2019-10-12]
time_sig = ~T[17:57:42.123456]
time_iso = "17:57:42.123456"
1570903062123 = Enc.timestamp_millis(ts_sig)
1570903062123 = Enc.timestamp_millis(ts_iso)
1570897662123 = Enc.timestamp_millis(ts_iso_tz)
1570903062123456 = Enc.timestamp_micros(ts_sig)
1570903062123456 = Enc.timestamp_micros(ts_iso)
1570897662123456 = Enc.timestamp_micros(ts_iso_tz)
18181 = Enc.date(date_sig)
18181 = Enc.date(date_iso)
# These are "naive" intervals from midnight, not timezoned:
64662123 = Enc.time_millis(time_sig)
64662123 = Enc.time_millis(time_iso)
64662123456 = Enc.time_micros(time_iso)
64662123456 = Enc.time_micros(time_sig)

~D[2019-10-12] = date_sig
~D[2019-10-12] = Dec.date(Enc.date(date_iso))
~U[2019-10-12 17:57:42.123456Z] = ts_sig
~U[2019-10-12 17:57:42.123Z]    = Dec.timestamp_millis(Enc.timestamp_millis(ts_iso))
~U[2019-10-12 17:57:42.123456Z] = Dec.timestamp_micros(Enc.timestamp_micros(ts_iso))
~U[2019-10-12 16:27:42.123456Z] = ts_sig_tz
~U[2019-10-12 16:27:42.123Z]    = Dec.timestamp_millis(Enc.timestamp_millis(ts_iso_tz))
~U[2019-10-12 16:27:42.123456Z] = Dec.timestamp_micros(Enc.timestamp_micros(ts_iso_tz))
~T[17:57:42.123456] = time_sig
~T[17:57:42.123] = Dec.time_millis(Enc.time_millis(time_iso))
~T[17:57:42.123456] = Dec.time_micros(Enc.time_micros(time_iso))