plotly · my-tien · Jun 29, 2026 · Jun 29, 2026 · Jun 29, 2026 · Jun 29, 2026
diff --git a/draftlogs/7877_fix.md b/draftlogs/7877_fix.md
@@ -0,0 +1,2 @@
+- Fix missing last period label when using a negative `ticklabelindex` in a chart where the last major tick is not visible [[#7877](https://github.com/plotly/plotly.js/pull/7877)]
+- Fix incorrect period label positioning when using `ticklabelindex` in a chart where not enough minor ticks are visible [[#7877](https://github.com/plotly/plotly.js/pull/7877)]
diff --git a/src/plots/cartesian/axes.js b/src/plots/cartesian/axes.js
diff --git a/test/image/baselines/date_axes_period2_ticklabelindex.png b/test/image/baselines/date_axes_period2_ticklabelindex.png
diff --git a/test/image/baselines/date_axes_period_ticklabelindex.png b/test/image/baselines/date_axes_period_ticklabelindex.png
diff --git a/test/image/baselines/ticklabelindex-2.png b/test/image/baselines/ticklabelindex-2.png
diff --git a/test/image/baselines/ticklabelindex.png b/test/image/baselines/ticklabelindex.png
diff --git a/test/image/mocks/date_axes_period2_ticklabelindex.json b/test/image/mocks/date_axes_period2_ticklabelindex.json
@@ -44,7 +44,7 @@
   "layout": {
     "showlegend": false,
     "width": 600,
-    "height": 500,
+    "height": 740,
     "yaxis": {
       "domain": [0, 0.04]
     },

diff --git a/test/image/mocks/ticklabelindex-2.json b/test/image/mocks/ticklabelindex-2.json
@@ -0,0 +1,68 @@
+{
+  "data": [
+    {
+      "x": [
+        "2020", "2021", "2022"
+      ],
+      "y": [
+        3, 2, 1
+      ]
+    },
+    {
+      "mode": "markers+text",
+      "texttemplate": "%{x|Q%q %y}",
+      "textposition": "top center",
+      "x": [
+        "2019-07-01", "2019-10-01", "2020-01-01", "2020-04-01", "2020-07-01"
+      ],
+      "y": [
+        2, 2, 2, 2, 2
+      ],
+      "yaxis": "y2",
+      "xaxis": "x2"
+    }
+  ],
+  "layout": {
+    "width": 600,
+    "height": 800,
+    "grid": {
+      "rows": 2,
+      "columns": 1,
+      "pattern": "independent"
+    },
+    "xaxis": {
+      "dtick": "M12",
+      "insiderange": [
+        "2020-03-27",
+        "2022-07-21"
+      ],
+      "tickformat": "%Y",
+      "ticklabelindex": -1,
+      "ticks": "outside",
+      "ticklen": 20,
+      "ticklabelmode": "period",
+      "type": "date",
+      "title": {
+        "text": "Should display 2 major ticks and labels 2020, 2021, 2022"
+      }
+    },
+    "xaxis2": {
+      "dtick": "M24",
+      "insiderange": [
+        "2019-03-01",
+        "2021-01-01"
+      ],
+      "tick0": "2021-01-01",
+      "tickformat": "%Y",
+      "ticklabelindex": -1,
+      "ticklabelmode": "period",
+      "ticklen": 20,
+      "type": "date",
+      "ticks": "outside",
+      "minor": { "dtick": "M12", "ticks": "outside", "ticklen": 5 },
+      "title": {
+        "text": "Should display 1 major tick, 1 minor tick and a label 2020 in between."
+      }
+    }
+  }
+}
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		- Fix missing last period label when using a negative `ticklabelindex` in a chart where the last major tick is not visible [[#7877](https://github.com/plotly/plotly.js/pull/7877)]
		- Fix incorrect period label positioning when using `ticklabelindex` in a chart where not enough minor ticks are visible [[#7877](https://github.com/plotly/plotly.js/pull/7877)]