From 5022088bea614377cc4cb49760e03270d10121e2 Mon Sep 17 00:00:00 2001
From: Steve Rowley <srowley@gmail.com>
Date: Sat, 2 May 2026 22:22:59 -0500
Subject: [PATCH] fix: support pin interpolation of temporal values

---
 lib/dux.ex              |  4 ++++
 test/dux/query_test.exs | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/lib/dux.ex b/lib/dux.ex
index 8e1ca11..a5a8416 100644
--- a/lib/dux.ex
+++ b/lib/dux.ex
@@ -2200,6 +2200,10 @@ defmodule Dux do
 
   defp encode_param(v) when is_integer(v), do: Integer.to_string(v)
   defp encode_param(v) when is_float(v), do: Float.to_string(v)
+  defp encode_param(%Date{} = v), do: "'#{Date.to_iso8601(v)}'"
+  defp encode_param(%Time{} = v), do: "'#{Time.to_iso8601(v)}'"
+  defp encode_param(%NaiveDateTime{} = v), do: "'#{NaiveDateTime.to_iso8601(v)}'"
+  defp encode_param(%DateTime{} = v), do: "'#{DateTime.to_iso8601(v)}'"
   defp encode_param(v) when is_binary(v), do: "'#{String.replace(v, "'", "''")}'"
   defp encode_param(true), do: "true"
   defp encode_param(false), do: "false"
diff --git a/test/dux/query_test.exs b/test/dux/query_test.exs
index 7ac48b5..6e37c10 100644
--- a/test/dux/query_test.exs
+++ b/test/dux/query_test.exs
@@ -98,6 +98,17 @@ defmodule Dux.QueryTest do
       assert result["name"] == ["Alice"]
     end
 
+    test "date pin" do
+      cutoff = ~D[2024-01-01]
+
+      result =
+        Dux.from_query("SELECT DATE '2023-12-30' AS d UNION ALL SELECT DATE '2024-01-02' AS d")
+        |> Dux.filter(d > ^cutoff)
+        |> Dux.to_columns()
+
+      assert result["d"] == [~D[2024-01-02]]
+    end
+
     test "multiple pins" do
       lo = 5
       hi = 15