diff --git a/.gitignore b/.gitignore
index 0bab332..969d006 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
 .eunit
-ebin/*.beam
\ No newline at end of file
+ebin
diff --git a/Makefile b/Makefile
new file mode 100755
index 0000000..95c9a78
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,10 @@
+PROJECT = iso8601
+
+# Options
+ERLC_OPTS  = +debug_info +nowarn_shadow_vars +warnings_as_errors
+EUNIT_OPTS = [verbose]
+
+# Standard targets
+include erlang.mk
+
+# eof
diff --git a/erlang.mk b/erlang.mk
new file mode 100644
index 0000000..af56d91
--- /dev/null
+++ b/erlang.mk
@@ -0,0 +1,314 @@
+# Copyright (c) 2013-2014, Loïc Hoguin <essen@ninenines.eu>
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# Project.
+
+PROJECT ?= $(notdir $(CURDIR))
+
+# Packages database file.
+
+PKG_FILE ?= $(CURDIR)/.erlang.mk.packages.v1
+export PKG_FILE
+
+PKG_FILE_URL ?= https://raw.github.com/extend/erlang.mk/master/packages.v1.tsv
+
+define get_pkg_file
+	wget --no-check-certificate -O $(PKG_FILE) $(PKG_FILE_URL) || rm $(PKG_FILE)
+endef
+
+# Verbosity and tweaks.
+
+V ?= 0
+
+appsrc_verbose_0 = @echo " APP   " $(PROJECT).app.src;
+appsrc_verbose = $(appsrc_verbose_$(V))
+
+erlc_verbose_0 = @echo " ERLC  " $(filter %.erl %.core,$(?F));
+erlc_verbose = $(erlc_verbose_$(V))
+
+xyrl_verbose_0 = @echo " XYRL  " $(filter %.xrl %.yrl,$(?F));
+xyrl_verbose = $(xyrl_verbose_$(V))
+
+dtl_verbose_0 = @echo " DTL   " $(filter %.dtl,$(?F));
+dtl_verbose = $(dtl_verbose_$(V))
+
+gen_verbose_0 = @echo " GEN   " $@;
+gen_verbose = $(gen_verbose_$(V))
+
+.PHONY: rel clean-rel all clean-all app clean deps clean-deps \
+	docs clean-docs build-tests tests build-plt dialyze eunit
+
+# Release.
+
+RELX_CONFIG ?= $(CURDIR)/relx.config
+
+ifneq ($(wildcard $(RELX_CONFIG)),)
+
+RELX ?= $(CURDIR)/relx
+export RELX
+
+RELX_URL ?= https://github.com/erlware/relx/releases/download/v0.6.0/relx
+RELX_OPTS ?=
+RELX_OUTPUT_DIR ?= _rel
+
+ifneq ($(firstword $(subst -o,,$(RELX_OPTS))),)
+	RELX_OUTPUT_DIR = $(firstword $(subst -o,,$(RELX_OPTS)))
+endif
+
+define get_relx
+	wget -O $(RELX) $(RELX_URL) || rm $(RELX)
+	chmod +x $(RELX)
+endef
+
+rel: clean-rel all $(RELX)
+	@$(RELX) -c $(RELX_CONFIG) $(RELX_OPTS)
+
+$(RELX):
+	@$(call get_relx)
+
+clean-rel:
+	$(gen_verbose) rm -rf $(RELX_OUTPUT_DIR)
+
+endif
+
+# Deps directory.
+
+DEPS_DIR ?= $(CURDIR)/deps
+export DEPS_DIR
+
+REBAR_DEPS_DIR = $(DEPS_DIR)
+export REBAR_DEPS_DIR
+
+ALL_DEPS_DIRS = $(addprefix $(DEPS_DIR)/,$(DEPS))
+ALL_TEST_DEPS_DIRS = $(addprefix $(DEPS_DIR)/,$(TEST_DEPS))
+
+# Application.
+
+ifeq ($(filter $(DEPS_DIR),$(subst :, ,$(ERL_LIBS))),)
+ifeq ($(ERL_LIBS),)
+	ERL_LIBS = $(DEPS_DIR)
+else
+	ERL_LIBS := $(ERL_LIBS):$(DEPS_DIR)
+endif
+endif
+export ERL_LIBS
+
+ERLC_OPTS ?= -Werror +debug_info +warn_export_all +warn_export_vars \
+	+warn_shadow_vars +warn_obsolete_guard # +bin_opt_info +warn_missing_spec
+COMPILE_FIRST ?=
+COMPILE_FIRST_PATHS = $(addprefix src/,$(addsuffix .erl,$(COMPILE_FIRST)))
+
+all: deps app
+
+clean-all: clean clean-deps clean-docs
+	$(gen_verbose) rm -rf .$(PROJECT).plt $(DEPS_DIR) logs
+
+app: ebin/$(PROJECT).app
+	$(eval MODULES := $(shell find ebin -type f -name \*.beam \
+		| sed 's/ebin\///;s/\.beam/,/' | sed '$$s/.$$//'))
+	$(appsrc_verbose) cat src/$(PROJECT).app.src \
+		| sed 's/{modules,[[:space:]]*\[\]}/{modules, \[$(MODULES)\]}/' \
+		> ebin/$(PROJECT).app
+
+define compile_erl
+	$(erlc_verbose) erlc -v $(ERLC_OPTS) -o ebin/ \
+		-pa ebin/ -I include/ $(COMPILE_FIRST_PATHS) $(1)
+endef
+
+define compile_xyrl
+	$(xyrl_verbose) erlc -v -o ebin/ $(1)
+	$(xyrl_verbose) erlc $(ERLC_OPTS) -o ebin/ ebin/*.erl
+	@rm ebin/*.erl
+endef
+
+define compile_dtl
+	$(dtl_verbose) erl -noshell -pa ebin/ $(DEPS_DIR)/erlydtl/ebin/ -eval ' \
+		Compile = fun(F) -> \
+			Module = list_to_atom( \
+				string:to_lower(filename:basename(F, ".dtl")) ++ "_dtl"), \
+			erlydtl:compile(F, Module, [{out_dir, "ebin/"}]) \
+		end, \
+		_ = [Compile(F) || F <- string:tokens("$(1)", " ")], \
+		init:stop()'
+endef
+
+ebin/$(PROJECT).app: $(shell find src -type f -name \*.erl) \
+		$(shell find src -type f -name \*.core) \
+		$(shell find src -type f -name \*.xrl) \
+		$(shell find src -type f -name \*.yrl) \
+		$(shell find templates -type f -name \*.dtl 2>/dev/null)
+	@mkdir -p ebin/
+	$(if $(strip $(filter %.erl %.core,$?)), \
+		$(call compile_erl,$(filter %.erl %.core,$?)))
+	$(if $(strip $(filter %.xrl %.yrl,$?)), \
+		$(call compile_xyrl,$(filter %.xrl %.yrl,$?)))
+	$(if $(strip $(filter %.dtl,$?)), \
+		$(call compile_dtl,$(filter %.dtl,$?)))
+
+clean:
+	$(gen_verbose) rm -rf ebin/ test/*.beam erl_crash.dump .eunit
+
+# Dependencies.
+
+define get_dep
+	@mkdir -p $(DEPS_DIR)
+ifeq (,$(findstring pkg://,$(word 1,$(dep_$(1)))))
+	git clone -n -- $(word 1,$(dep_$(1))) $(DEPS_DIR)/$(1)
+else
+	@if [ ! -f $(PKG_FILE) ]; then $(call get_pkg_file); fi
+	git clone -n -- `awk 'BEGIN { FS = "\t" }; \
+		$$$$1 == "$(subst pkg://,,$(word 1,$(dep_$(1))))" { print $$$$2 }' \
+		$(PKG_FILE)` $(DEPS_DIR)/$(1)
+endif
+	cd $(DEPS_DIR)/$(1) ; git checkout -q $(word 2,$(dep_$(1)))
+endef
+
+define dep_target
+$(DEPS_DIR)/$(1):
+	$(call get_dep,$(1))
+endef
+
+$(foreach dep,$(DEPS),$(eval $(call dep_target,$(dep))))
+
+deps: $(ALL_DEPS_DIRS)
+	@for dep in $(ALL_DEPS_DIRS) ; do \
+		if [ -f $$dep/Makefile ] ; then \
+			$(MAKE) -C $$dep ; \
+		else \
+			echo "include $(CURDIR)/erlang.mk" | $(MAKE) -f - -C $$dep ; \
+		fi ; \
+	done
+
+clean-deps:
+	@for dep in $(ALL_DEPS_DIRS) ; do \
+		if [ -f $$dep/Makefile ] ; then \
+			$(MAKE) -C $$dep clean ; \
+		else \
+			echo "include $(CURDIR)/erlang.mk" | $(MAKE) -f - -C $$dep clean ; \
+		fi ; \
+	done
+
+# Documentation.
+
+EDOC_OPTS ?=
+
+docs: clean-docs
+	$(gen_verbose) erl -noshell \
+		-eval 'edoc:application($(PROJECT), ".", [$(EDOC_OPTS)]), init:stop().'
+
+clean-docs:
+	$(gen_verbose) rm -f doc/*.css doc/*.html doc/*.png doc/edoc-info
+
+# Tests.
+
+$(foreach dep,$(TEST_DEPS),$(eval $(call dep_target,$(dep))))
+
+TEST_ERLC_OPTS ?= +debug_info +warn_export_vars +warn_shadow_vars +warn_obsolete_guard
+TEST_ERLC_OPTS += -DTEST=1 -DEXTRA=1 +'{parse_transform, eunit_autoexport}'
+
+build-test-deps: $(ALL_TEST_DEPS_DIRS)
+	@for dep in $(ALL_TEST_DEPS_DIRS) ; do $(MAKE) -C $$dep; done
+
+build-tests: build-test-deps
+	$(gen_verbose) erlc -v $(TEST_ERLC_OPTS) -o test/ \
+		$(wildcard test/*.erl test/*/*.erl) -pa ebin/
+
+CT_OPTS ?=
+CT_RUN = ct_run \
+	-no_auto_compile \
+	-noshell \
+	-pa $(realpath ebin) $(DEPS_DIR)/*/ebin \
+	-dir test \
+	-logdir logs \
+	$(CT_OPTS)
+
+CT_SUITES ?=
+
+define test_target
+test_$(1): ERLC_OPTS = $(TEST_ERLC_OPTS)
+test_$(1): clean deps app build-tests
+	@if [ -d "test" ] ; \
+	then \
+		mkdir -p logs/ ; \
+		$(CT_RUN) -suite $(addsuffix _SUITE,$(1)) ; \
+	fi
+	$(gen_verbose) rm -f test/*.beam
+endef
+
+$(foreach test,$(CT_SUITES),$(eval $(call test_target,$(test))))
+
+tests: ERLC_OPTS = $(TEST_ERLC_OPTS)
+tests: clean deps app build-tests
+	@if [ -d "test" ] ; \
+	then \
+		mkdir -p logs/ ; \
+		$(CT_RUN) -suite $(addsuffix _SUITE,$(CT_SUITES)) ; \
+	fi
+	$(gen_verbose) rm -f test/*.beam
+
+# Dialyzer.
+
+DIALYZER_PLT ?= $(CURDIR)/.$(PROJECT).plt
+export DIALYZER_PLT
+
+PLT_APPS ?=
+DIALYZER_OPTS ?= -Werror_handling -Wrace_conditions \
+	-Wunmatched_returns # -Wunderspecs
+
+build-plt: deps app
+	@dialyzer --build_plt --apps erts kernel stdlib $(PLT_APPS) $(ALL_DEPS_DIRS)
+
+dialyze:
+	@dialyzer --src src --no_native $(DIALYZER_OPTS)
+
+eunit: deps .eunit
+	@export EUNIT=$(EUNIT_OPTS) && erl \
+		-pa .eunit -pa $(DEPS_DIR)/*/ebin/ \
+		-run eunit test .eunit/*.beam \
+		-run init stop \
+		-noshell -noinput
+
+.eunit: $(shell find src -type f -name \*.erl) \
+			$(shell find test -type f -name \*.erl)
+	@mkdir -p .eunit
+	$(erlc_verbose) erlc -v \
+		-o .eunit/ \
+		-I include/ \
+		$(ERLC_OPTS) \
+		-DTEST \
+		$?
+
+# Packages.
+
+$(PKG_FILE):
+	@$(call get_pkg_file)
+
+pkg-list: $(PKG_FILE)
+	@cat $(PKG_FILE) | awk 'BEGIN { FS = "\t" }; { print \
+		"Name:\t\t" $$1 "\n" \
+		"Repository:\t" $$2 "\n" \
+		"Website:\t" $$3 "\n" \
+		"Description:\t" $$4 "\n" }'
+
+ifdef q
+pkg-search: $(PKG_FILE)
+	@cat $(PKG_FILE) | grep -i ${q} | awk 'BEGIN { FS = "\t" }; { print \
+		"Name:\t\t" $$1 "\n" \
+		"Repository:\t" $$2 "\n" \
+		"Website:\t" $$3 "\n" \
+		"Description:\t" $$4 "\n" }'
+else
+pkg-search:
+	@echo "Usage: make pkg-search q=STRING"
+endif