diff --git a/registries/_format/date-time-local.md b/registries/_format/date-time-local.md
new file mode 100644
index 0000000000..28b1d83c98
--- /dev/null
+++ b/registries/_format/date-time-local.md
@@ -0,0 +1,15 @@
+---
+owner: ya7010
+issue: 4759
+description: RFC3339 date-time without the timezone component
+base_type: string
+layout: default
+source_label: RFC 3339
+source: https://www.rfc-editor.org/rfc/rfc3339#section-5.6
+---
+
+{% capture summary %}
+The `{{page.slug}}` format represents a RFC3339 date-time without timezone.
+{% endcapture %}
+
+{% include format-entry.md summary=summary %}
diff --git a/registries/_format/time-local.md b/registries/_format/time-local.md
new file mode 100644
index 0000000000..3416704aae
--- /dev/null
+++ b/registries/_format/time-local.md
@@ -0,0 +1,15 @@
+---
+owner: ya7010
+issue: 4759
+description: RFC3339 time without the timezone component
+base_type: string
+layout: default
+source_label: RFC 3339
+source: https://www.rfc-editor.org/rfc/rfc3339#section-5.6
+---
+
+{% capture summary %}
+The `{{page.slug}}` format represents a RFC3339 time without timezone.
+{% endcapture %}
+
+{% include format-entry.md summary=summary %}