diff --git a/charts.html b/charts.html
index c8e43f6..044dc32 100644
--- a/charts.html
+++ b/charts.html
@@ -15,12 +15,14 @@
     const humidityColor = 'rgb(45,141,45)';
     const tempColor = 'rgb(0,134,222)';
     const co2Color = 'rgb(194,30,30)';
+    let minutesDisplayed = 60;
 
     async function getData() {
         let urlEndpoint = "/" + ROOT_URL + "data/";
         const pathname = window.location.pathname;
         if (pathname.includes("since")) {
-            urlEndpoint += "since/" + pathname.slice(pathname.lastIndexOf("/") + 1);
+            minutesDisplayed = Number(pathname.slice(pathname.lastIndexOf("/") + 1));
+            urlEndpoint += "since/" + minutesDisplayed;
         }
         const data = await fetch(urlEndpoint);
         return transformData(await data.json());
@@ -127,16 +129,30 @@
         setInterval(async () => {
             const newDatum = await fetch("/" + ROOT_URL + "data/last/");
             const snapshot = (await newDatum.json()).snapshots[0];
-            chart.data.datasets[0].data.splice(0, 1);
-            chart.data.datasets[0].data.push({x: snapshot.time, y: snapshot.humidity});
-            chart.data.datasets[1].data.splice(0, 1);
-            chart.data.datasets[1].data.push({x: snapshot.time, y: snapshot.temp});
-            chart.data.datasets[2].data.splice(0, 1);
-            chart.data.datasets[2].data.push({x: snapshot.time, y: snapshot.co2});
-            chart.update(0);
+            if (snapshot.time !== chart.data.datasets[0].x) {
+                removeExpiredData(chart);
+                insertSnapshot(chart, snapshot);
+            }
         }, 10 * 1000);
     }
 
+    function insertSnapshot(chart, snapshot) {
+        chart.data.datasets[0].data.push({x: snapshot.time, y: snapshot.humidity});
+        chart.data.datasets[1].data.push({x: snapshot.time, y: snapshot.temp});
+        chart.data.datasets[2].data.push({x: snapshot.time, y: snapshot.co2});
+        chart.update(0);
+    }
+
+    function removeExpiredData(chart) {
+        for (let i = 0; i < chart.data.datasets[0].data.length; i++) {
+            if ((Date.now() - Date.parse(chart.data.datasets[0].data[i].x)) > minutesDisplayed * 60000) {
+                chart.data.datasets[0].data.splice(i, 1);
+                chart.data.datasets[1].data.splice(i, 1);
+                chart.data.datasets[2].data.splice(i, 1);
+            }
+        }
+    }
+
     initChart();
 </script>