diff --git a/server/model/monitor.js b/server/model/monitor.js
index bd0597854..6c6ccbcc2 100644
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@@ -15,6 +15,7 @@ const { UptimeKumaServer } = require("../uptime-kuma-server");
 const { CacheableDnsHttpAgent } = require("../cacheable-dns-http-agent");
 const { DockerHost } = require("../docker");
 const Maintenance = require("./maintenance");
+const { UptimeCacheList } = require("../uptime-cache-list");
 
 /**
  * status:
@@ -714,6 +715,7 @@ class Monitor extends BeanModel {
             }
 
             log.debug("monitor", `[${this.name}] Send to socket`);
+            UptimeCacheList.clearCache(this.id);
             io.to(this.user_id).emit("heartbeat", bean.toJSON());
             Monitor.sendStats(io, this.id, this.user_id);
 
@@ -898,7 +900,15 @@ class Monitor extends BeanModel {
      * @param {number} duration Hours
      * @param {number} monitorID ID of monitor to calculate
      */
-    static async calcUptime(duration, monitorID) {
+    static async calcUptime(duration, monitorID, forceNoCache = false) {
+
+        if (!forceNoCache) {
+            let cachedUptime = UptimeCacheList.getUptime(monitorID, duration);
+            if (cachedUptime != null) {
+                return cachedUptime;
+            }
+        }
+
         const timeLogger = new TimeLogger();
 
         const startTime = R.isoDateTime(dayjs.utc().subtract(duration, "hour"));
@@ -957,6 +967,9 @@ class Monitor extends BeanModel {
             }
         }
 
+        // Cache
+        UptimeCacheList.addUptime(monitorID, duration, uptime);
+
         return uptime;
     }
 
diff --git a/server/uptime-cache-list.js b/server/uptime-cache-list.js
new file mode 100644
index 000000000..1347968fa
--- /dev/null
+++ b/server/uptime-cache-list.js
@@ -0,0 +1,39 @@
+const { log } = require("../src/util");
+class UptimeCacheList {
+    /**
+     * list[monitorID][duration]
+     */
+    static list = {};
+
+    /**
+     *
+     * @param monitorID
+     * @param duration
+     * @return number
+     */
+    static getUptime(monitorID, duration) {
+        if (UptimeCacheList.list[monitorID] && UptimeCacheList.list[monitorID][duration]) {
+            log.debug("UptimeCacheList", "getUptime: " + monitorID + " " + duration);
+            return UptimeCacheList.list[monitorID][duration];
+        } else {
+            return null;
+        }
+    }
+
+    static addUptime(monitorID, duration, uptime) {
+        log.debug("UptimeCacheList", "addUptime: " + monitorID + " " + duration);
+        if (!UptimeCacheList.list[monitorID]) {
+            UptimeCacheList.list[monitorID] = {};
+        }
+        UptimeCacheList.list[monitorID][duration] = uptime;
+    }
+
+    static clearCache(monitorID) {
+        log.debug("UptimeCacheList", "clearCache: " + monitorID);
+        delete UptimeCacheList.list[monitorID];
+    }
+}
+
+module.exports = {
+    UptimeCacheList,
+};