diff --git a/CHANGELOG.md b/CHANGELOG.md
index de108e0..240d795 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
+# Changelog for Cldr_Calendars_Ethiopic v0.3.0
+
+This is the changelog for ex_cldr_calendars_coptic v0.3.0 released on March 18th, 2021.  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_calendars_ethiopic/tags)
+
+### Bug Fixes
+
+* Require Elixir 1.10 or later
+
+* Update `Cldr.Calendar.Ethiopic.day_of_week/3` to be `Cldr.Calendar.Ethiopic.day_of_week/4` as required by Elixir 1.10.
+
 # Changelog for Cldr_Calendars_Ethiopic v0.2.0
 
 This is the changelog for ex_cldr_calendars_coptic v0.2.0 released on July 3rd, 2020  For older changelogs please consult the release tag on [GitHub](https://github.com/elixir-cldr/cldr_calendars_ethiopic/tags)
diff --git a/lib/cldr/calendar/ethiopic.ex b/lib/cldr/calendar/ethiopic.ex
index 00092e8..278c8b2 100644
--- a/lib/cldr/calendar/ethiopic.ex
+++ b/lib/cldr/calendar/ethiopic.ex
@@ -166,13 +166,32 @@ defmodule Cldr.Calendar.Ethiopic do
   It is an integer from 1 to 7, where 1 is Monday and 7 is Sunday.
 
   """
-  @spec day_of_week(year, month, day) :: 1..7
-  @impl true
   @epoch_day_of_week 6
-  def day_of_week(year, month, day) do
-    days = date_to_iso_days(year, month, day)
-    days_after_saturday = rem(days, 7)
-    Cldr.Math.amod(days_after_saturday + @epoch_day_of_week, @days_in_week)
+
+  if Code.ensure_loaded?(Date) && function_exported?(Date, :day_of_week, 2) do
+    @last_day_of_week 5
+
+    @spec day_of_week(year, month, day, :default | atom()) ::
+        {Calendar.day_of_week(), first_day_of_week :: non_neg_integer(),
+          last_day_of_week :: non_neg_integer()}
+
+    @impl true
+    def day_of_week(year, month, day, :default) do
+      days = date_to_iso_days(year, month, day)
+      days_after_saturday = rem(days, 7)
+      day = Cldr.Math.amod(days_after_saturday + @epoch_day_of_week, @days_in_week)
+
+      {day, @epoch_day_of_week, @last_day_of_week}
+    end
+  else
+    @spec day_of_week(year, month, day) :: 1..7
+
+    @impl true
+    def day_of_week(year, month, day) do
+      days = date_to_iso_days(year, month, day)
+      days_after_saturday = rem(days, 7)
+      Cldr.Math.amod(days_after_saturday + @epoch_day_of_week, @days_in_week)
+    end
   end
 
   @doc """
diff --git a/mix.exs b/mix.exs
index 09daeb0..7d0cf04 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,13 +1,13 @@
 defmodule Cldr.Calendars.Ethiopic.MixProject do
   use Mix.Project
 
-  @version "0.2.0"
+  @version "0.3.0"
 
   def project do
     [
       app: :ex_cldr_calendars_ethiopic,
       version: @version,
-      elixir: "~> 1.8",
+      elixir: "~> 1.10",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
       source_url: "https://github.com/elixir-cldr/cldr_calendars_ethiopic",
diff --git a/mix.lock b/mix.lock
index 15e8607..d73cd75 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,24 +1,25 @@
 %{
   "astro": {:hex, :astro, "0.3.0", "6b17a107d2985d87933f6ac89b4fe653009318757b28c769d7d96ab6c73e84da", [:mix], [{:geo, "~> 3.0", [hex: :geo, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:tz_world, "~> 0.2", [hex: :tz_world, repo: "hexpm", optional: false]}, {:tzdata, "~> 1.0", [hex: :tzdata, repo: "hexpm", optional: false]}], "hexpm"},
   "certifi": {:hex, :certifi, "2.5.1", "867ce347f7c7d78563450a18a6a28a8090331e77fa02380b4a21962a65d36ee5", [:rebar3], [{:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}], "hexpm"},
-  "cldr_utils": {:hex, :cldr_utils, "2.9.1", "be714403abe1a7abed5ee4f7dd3823a9067f96ab4b0613a454177b51ca204236", [:mix], [{:decimal, "~> 1.6", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm", "6cba0a485f57feb773291ca1816469ddd887e22d73d9b12a1b207d82a67a4e71"},
-  "decimal": {:hex, :decimal, "1.8.1", "a4ef3f5f3428bdbc0d35374029ffcf4ede8533536fa79896dd450168d9acdf3c", [:mix], [], "hexpm", "3cb154b00225ac687f6cbd4acc4b7960027c757a5152b369923ead9ddbca7aec"},
-  "earmark": {:hex, :earmark, "1.4.9", "837e4c1c5302b3135e9955f2bbf52c6c52e950c383983942b68b03909356c0d9", [:mix], [{:earmark_parser, ">= 1.4.9", [hex: :earmark_parser, repo: "hexpm", optional: false]}], "hexpm", "0d72df7d13a3dc8422882bed5263fdec5a773f56f7baeb02379361cb9e5b0d8e"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.9", "819bda2049e6ee1365424e4ced1ba65806eacf0d2867415f19f3f80047f8037b", [:mix], [], "hexpm", "8bf54fddabf2d7e137a0c22660e71b49d5a0a82d1fb05b5af62f2761cd6485c4"},
-  "ex_cldr": {:hex, :ex_cldr, "2.16.1", "905b03c38b5fb51668a347f2e6b586bcb2c0816cd98f7d913104872c43cbc61f", [:mix], [{:castore, "~> 0.1", [hex: :castore, repo: "hexpm", optional: true]}, {:certifi, "~> 2.5", [hex: :certifi, repo: "hexpm", optional: true]}, {:cldr_utils, "~> 2.9", [hex: :cldr_utils, repo: "hexpm", optional: false]}, {:decimal, "~> 1.6", [hex: :decimal, repo: "hexpm", optional: false]}, {:gettext, "~> 0.13", [hex: :gettext, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:plug, "~> 1.9", [hex: :plug, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: true]}], "hexpm", "006e500769982e57e6f3e32cbc4664345f78b014bb5ff48ddc394d67c86c1a8d"},
-  "ex_cldr_calendars": {:hex, :ex_cldr_calendars, "1.9.0", "ace1c57ba3850753c9ac6ddb89dc0c9a9e5e1c57ecad587e21c8925ad30a3838", [:mix], [{:calendar_interval, "~> 0.2", [hex: :calendar_interval, repo: "hexpm", optional: true]}, {:earmark, "~> 1.0", [hex: :earmark, repo: "hexpm", optional: false]}, {:ex_cldr_numbers, "~> 2.13", [hex: :ex_cldr_numbers, repo: "hexpm", optional: false]}, {:ex_cldr_units, "~> 3.0", [hex: :ex_cldr_units, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "a4b07773e2a326474f44a6bc51fffbec634859a1bad5cc6e6eb55eba45115541"},
-  "ex_cldr_currencies": {:hex, :ex_cldr_currencies, "2.5.0", "e369ae3c1cd5cd20aa20988b153fd2902b4ab08aec63ca8757d7104bdb79f867", [:mix], [{:ex_cldr, "~> 2.14", [hex: :ex_cldr, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "ba16b1df60bcec52c986481bbdfa7cfaec899b610f869d2b3c5a9a8149f67668"},
-  "ex_cldr_numbers": {:hex, :ex_cldr_numbers, "2.15.1", "dced7ffee69c4830593258b69b294adb4c65cf539e1d8ae0a4de31cfc8aa56a0", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ex_cldr, "~> 2.15", [hex: :ex_cldr, repo: "hexpm", optional: false]}, {:ex_cldr_currencies, "~> 2.5", [hex: :ex_cldr_currencies, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "c6a4b69ef80b8ffbb6c8fb69a2b365ba542580e0f76a15d8c6ee9142bd1b97ea"},
-  "ex_doc": {:hex, :ex_doc, "0.22.1", "9bb6d51508778193a4ea90fa16eac47f8b67934f33f8271d5e1edec2dc0eee4c", [:mix], [{:earmark, "~> 1.4.0", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "d957de1b75cb9f78d3ee17820733dc4460114d8b1e11f7ee4fd6546e69b1db60"},
+  "cldr_utils": {:hex, :cldr_utils, "2.15.1", "1136987437ac4821f3ec7d46ff150f1c020a1f79730ff1252bfa7681ed577f31", [:mix], [{:castore, "~> 0.1", [hex: :castore, repo: "hexpm", optional: true]}, {:certifi, "~> 2.5", [hex: :certifi, repo: "hexpm", optional: true]}, {:decimal, "~> 1.9 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm", "ca3c8da0aab18b4d944541392e9548422e30854e3a9d7768dc629c8123f8efb8"},
+  "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},
+  "earmark": {:hex, :earmark, "1.4.14", "d04572cef64dd92726a97d92d714e38d6e130b024ea1b3f8a56e7de66ec04e50", [:mix], [{:earmark_parser, ">= 1.4.12", [hex: :earmark_parser, repo: "hexpm", optional: false]}], "hexpm", "df338b8b1852ee425180b276c56c6941cb12220e04fe8718fe4acbdd35fd699f"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.12", "b245e875ec0a311a342320da0551da407d9d2b65d98f7a9597ae078615af3449", [:mix], [], "hexpm", "711e2cc4d64abb7d566d43f54b78f7dc129308a63bc103fbd88550d2174b3160"},
+  "ex_cldr": {:hex, :ex_cldr, "2.19.0", "61e789016dff00f24a28b26632f6240efe8257ad4f651741e889d8929a0fd075", [:mix], [{:castore, "~> 0.1", [hex: :castore, repo: "hexpm", optional: true]}, {:certifi, "~> 2.5", [hex: :certifi, repo: "hexpm", optional: true]}, {:cldr_utils, "~> 2.12", [hex: :cldr_utils, repo: "hexpm", optional: false]}, {:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:gettext, "~> 0.13", [hex: :gettext, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}, {:plug, "~> 1.9", [hex: :plug, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: true]}], "hexpm", "fccdb406d66da75991e37e4b7b59aa2e1c8242f41822924f9560453610123d84"},
+  "ex_cldr_calendars": {:hex, :ex_cldr_calendars, "1.12.0", "0cf7c804937a93baa9c3b471667ad05c478942865cc457e8397b5d83fc6f2c7a", [:mix], [{:calendar_interval, "~> 0.2", [hex: :calendar_interval, repo: "hexpm", optional: true]}, {:earmark, "~> 1.0", [hex: :earmark, repo: "hexpm", optional: false]}, {:ex_cldr_numbers, "~> 2.16", [hex: :ex_cldr_numbers, repo: "hexpm", optional: false]}, {:ex_cldr_units, "~> 3.3", [hex: :ex_cldr_units, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "edcb91ec52ee4e24a928e2bcf6d3354da465eced42887fbdb3f878a7a329963f"},
+  "ex_cldr_currencies": {:hex, :ex_cldr_currencies, "2.8.0", "b2ecc94e9fa4b8ec07614830f4d6e811e5df5e7679c6d2be92f4fe4f31184913", [:mix], [{:ex_cldr, "~> 2.18", [hex: :ex_cldr, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "a39780667b73bfd3d2bd08e61981bca23a97912b86f3236042850ecb062f48eb"},
+  "ex_cldr_numbers": {:hex, :ex_cldr_numbers, "2.16.1", "aea1cecbf19dfb6ac82658d05685015172866cf1a4ce0778f58157442ccf015d", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ex_cldr, "~> 2.18", [hex: :ex_cldr, repo: "hexpm", optional: false]}, {:ex_cldr_currencies, "~> 2.8", [hex: :ex_cldr_currencies, repo: "hexpm", optional: false]}, {:ex_doc, "~> 0.18", [hex: :ex_doc, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm", "ba7a6f9f50aaa7759d05e508a333747cf670c823b2857780b025f3c421f4f1d3"},
+  "ex_doc": {:hex, :ex_doc, "0.24.0", "2df14354835afaabdf87cb2971ea9485d8a36ff590e4b6c250b4f60c8fdf9143", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "a0f4bcff21ceebea48414e49885d2a3e542200f76a2facf3f8faa54935eeb721"},
   "geo": {:hex, :geo, "3.3.2", "30c7b458bcb0ab1ca73a997b26d22c68643d9ffe1726e475e0759499b6024cff", [:mix], [], "hexpm"},
   "hackney": {:hex, :hackney, "1.15.2", "07e33c794f8f8964ee86cebec1a8ed88db5070e52e904b8f12209773c1036085", [:rebar3], [{:certifi, "2.5.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.5", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm"},
   "idna": {:hex, :idna, "6.0.0", "689c46cbcdf3524c44d5f3dde8001f364cd7608a99556d8fbd8239a5798d4c10", [:rebar3], [{:unicode_util_compat, "0.4.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm"},
-  "jason": {:hex, :jason, "1.2.1", "12b22825e22f468c02eb3e4b9985f3d0cb8dc40b9bd704730efa11abd2708c44", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "b659b8571deedf60f79c5a608e15414085fa141344e2716fbd6988a084b5f993"},
-  "makeup": {:hex, :makeup, "1.0.3", "e339e2f766d12e7260e6672dd4047405963c5ec99661abdc432e6ec67d29ef95", [:mix], [{:nimble_parsec, "~> 0.5", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "2e9b4996d11832947731f7608fed7ad2f9443011b3b479ae288011265cdd3dad"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.14.1", "4f0e96847c63c17841d42c08107405a005a2680eb9c7ccadfd757bd31dabccfb", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "f2438b1a80eaec9ede832b5c41cd4f373b38fd7aa33e3b22d9db79e640cbde11"},
+  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
+  "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.15.1", "b5888c880d17d1cc3e598f05cdb5b5a91b7b17ac4eaf5f297cb697663a1094dd", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.1", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "db68c173234b07ab2a07f645a5acdc117b9f99d69ebf521821d89690ae6c6ec8"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm"},
-  "nimble_parsec": {:hex, :nimble_parsec, "0.6.0", "32111b3bf39137144abd7ba1cce0914533b2d16ef35e8abc5ec8be6122944263", [:mix], [], "hexpm", "27eac315a94909d4dc68bc07a4a83e06c8379237c5ea528a9acff4ca1c873c52"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.1.0", "3a6fca1550363552e54c216debb6a9e95bd8d32348938e13de5eda962c0d7f89", [:mix], [], "hexpm", "08eb32d66b706e913ff748f11694b17981c0b04a33ef470e33e11b3d3ac8f54b"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.5", "6eaf7ad16cb568bb01753dbbd7a95ff8b91c7979482b95f38443fe2c8852a79b", [:make, :mix, :rebar3], [], "hexpm"},
   "stream_data": {:hex, :stream_data, "0.5.0", "b27641e58941685c75b353577dc602c9d2c12292dd84babf506c2033cd97893e", [:mix], [], "hexpm", "012bd2eec069ada4db3411f9115ccafa38540a3c78c4c0349f151fc761b9e271"},