From 0f9d91d83937e36ef49e1d5a7f51726b7e843fce Mon Sep 17 00:00:00 2001
From: Goheer <145010056+xecanto@users.noreply.github.com>
Date: Sat, 17 Oct 2026 16:28:42 +0500
Subject: [PATCH] Show pre-1970 features in TimestampedGeoJson

Without a duration, Leaflet.TimeDimension uses 0 as the lower bound when
it filters features, so a feature whose times are all before 1970 is
never drawn. Use -Infinity instead when there is no duration.
---
 folium/plugins/timestamped_geo_json.py     | 13 ++++++++++++-
 tests/plugins/test_timestamped_geo_json.py | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/folium/plugins/timestamped_geo_json.py b/folium/plugins/timestamped_geo_json.py
index 11d1deae63..11023bfca1 100644
--- a/folium/plugins/timestamped_geo_json.py
+++ b/folium/plugins/timestamped_geo_json.py
@@ -138,7 +138,18 @@ class TimestampedGeoJson(JSCSSMixin, MacroElement):
                     addlastPoint: {{ this.add_last_point|tojson }},
                     duration: {{ this.duration }},
                 }
-            ).addTo({{this._parent.get_name()}});
+            );
+            // Without a duration Leaflet.TimeDimension starts at time 0, which
+            // hides features whose times are all before 1970.
+            {{this.get_name()}}._getFeatureBetweenDates = function(feature, minTime, maxTime) {
+                if (!this._duration) {
+                    minTime = -Infinity;
+                }
+                return L.TimeDimension.Layer.GeoJson.prototype._getFeatureBetweenDates.call(
+                    this, feature, minTime, maxTime
+                );
+            };
+            {{this.get_name()}}.addTo({{this._parent.get_name()}});
         {% endmacro %}
         """)  # noqa
 
diff --git a/tests/plugins/test_timestamped_geo_json.py b/tests/plugins/test_timestamped_geo_json.py
index 24ee9a12dc..dbe4199be0 100644
--- a/tests/plugins/test_timestamped_geo_json.py
+++ b/tests/plugins/test_timestamped_geo_json.py
@@ -190,7 +190,18 @@ def test_timestamped_geo_json():
                 addlastPoint: {{ this.add_last_point|tojson }},
                 duration: {{ this.duration }},
             }
-        ).addTo({{this._parent.get_name()}});
+        );
+        // Without a duration Leaflet.TimeDimension starts at time 0, which
+        // hides features whose times are all before 1970.
+        {{this.get_name()}}._getFeatureBetweenDates = function(feature, minTime, maxTime) {
+            if (!this._duration) {
+                minTime = -Infinity;
+            }
+            return L.TimeDimension.Layer.GeoJson.prototype._getFeatureBetweenDates.call(
+                this, feature, minTime, maxTime
+            );
+        };
+        {{this.get_name()}}.addTo({{this._parent.get_name()}});
     """)  # noqa
     expected = normalize(tmpl.render(this=tgj))
     assert expected in out