1 files changed, 25 insertions, 0 deletions
diff --git a/lib/util.ex b/lib/util.ex
index d35157b..ce46174 100644
--- a/lib/util.ex
+++ b/lib/util.ex
@@ -1,5 +1,30 @@
 defmodule Util do
 
+  def to_naive_date_time(naive = %NaiveDateTime{}), do: naive
+  def to_naive_date_time(datetime = %DateTime{}), do: DateTime.to_naive(datetime)
+  def to_naive_date_time(timestamp) when is_integer(timestamp) do
+    timestamp
+    |> to_date_time()
+    |> to_naive_date_time()
+  end
+
+  def to_date_time(naive_or_timestamp, timezone \\ "Europe/Paris")
+
+  def to_date_time(date = %DateTime{}, timezone) do
+    DateTime.shift_zone!(data, timezone, Tzdata.TimeZoneDatabase)
+  end
+
+  def to_date_time(naive = %NaiveDateTime{}, timezone) do
+    DateTime.from_naive!(naive, timezone, Tzdata.TimeZoneDatabase)
+  end
+
+  # todo: this is wrong.
+  def to_date_time(timestamp, timezone) when is_integer(timestamp) do
+    timestamp
+    |> DateTime.from_unix!(:millisecond)
+    |> DateTime.shift_zone!(timezone, Tzdata.TimeZoneDatabase)
+  end
+
   def plusminus(number) when number > 0, do: "+#{number}"
   def plusminus(0), do: "0"
   def plusminus(number) when number < 0, do: "#{number}"