Fix bug with date/datetime inputs

lib/outlook_web/components/core_components.ex

@@ -337,6 +337,16 @@ defmodule OutlookWeb.CoreComponents do
     """
   end
 
+  def input(assigns) when assigns.type in ~w(date datetime-local) and is_struct(assigns.value) do
+    format = case assigns.type do
+      "date" -> "%Y-%m-%d"
+      "datetime-local" -> "%Y-%m-%dT%H:%M"
+    end
+    assigns
+    |> assign(:value, Calendar.strftime(assigns.value, format))
+    |> input()
+  end
+
   def input(assigns) do
     ~H"""
     <div phx-feedback-for={@name}>