diff --git a/example.exs b/example.exs
index f96313f..be5d1f2 100755
--- a/example.exs
+++ b/example.exs
@@ -21,6 +21,8 @@ sheet1 = Sheet.with_name("First")
   |> Sheet.set_cell("A4", 1_448_882_362, yyyymmdd: true)
   # datetime: true ouputs date and time, yyyymmdd limits the output to just the date
   |> Sheet.set_cell("A5", 1_448_882_362, yyyymm: true)
+  # Date formatting can also be applied without setting the cell content
+  |> Sheet.set_cell("A6", "", datetime: true)
   # make some room in the first column, otherwise the date will only show up as ###
   |> Sheet.set_col_width("A", 18.0)
   # Cell borders
diff --git a/lib/elixlsx/util.ex b/lib/elixlsx/util.ex
index a2a73be..3aec898 100644
--- a/lib/elixlsx/util.ex
+++ b/lib/elixlsx/util.ex
@@ -231,6 +231,10 @@ defmodule Elixlsx.Util do
     {:formula, value}
   end
 
+  @spec to_excel_datetime(binary() | nil) :: binary()
+  def to_excel_datetime(nil), do: ""
+  def to_excel_datetime(""), do: ""
+
   @doc ~S"""
   Replace_all(input, [{search, replace}]).