diff --git a/db/patch-notification_sent_history.sql b/db/patch-notification_sent_history.sql
new file mode 100644
index 00000000..759eb382
--- /dev/null
+++ b/db/patch-notification_sent_history.sql
@@ -0,0 +1,18 @@
+-- You should not modify if this have pushed to Github, unless it does serious wrong with the db.
+BEGIN TRANSACTION;
+
+CREATE TABLE [notification_sent_history] (
+    [id] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+    [type] VARCHAR(50) NOT NULL,
+    [monitor_id] INTEGER NOT NULL,
+    [days] INTEGER NOT NULL,
+    UNIQUE([type], [monitor_id], [days])
+);
+
+CREATE INDEX [good_index] ON [notification_sent_history] (
+    [type],
+    [monitor_id],
+    [days]
+);
+
+COMMIT;
diff --git a/server/database.js b/server/database.js
index 98494251..41d91e85 100644
--- a/server/database.js
+++ b/server/database.js
@@ -51,6 +51,7 @@ class Database {
         "patch-monitor-push_token.sql": true,
         "patch-http-monitor-method-body-and-headers.sql": true,
         "patch-2fa-invalidate-used-token.sql": true,
+        "patch-notification_sent_history.sql": true,
     }
 
     /**
diff --git a/server/jobs.js b/server/jobs.js
index 5a92893b..0469d5ca 100644
--- a/server/jobs.js
+++ b/server/jobs.js
@@ -7,10 +7,6 @@ const jobs = [
         name: "clear-old-data",
         interval: "at 03:14",
     },
-    {
-        name: "certificate-notification",
-        interval: "60 seconds",         // TODO: Production should be larger
-    },
 ];
 
 const initBackgroundJobs = function (args) {
diff --git a/server/jobs/certificate-notification.js b/server/jobs/certificate-notification.js
deleted file mode 100644
index 2bada346..00000000
--- a/server/jobs/certificate-notification.js
+++ /dev/null
@@ -1,13 +0,0 @@
-const { log, exit, connectDb } = require("./util-worker");
-const { R } = require("redbean-node");
-const { setSetting, setting } = require("../util-server");
-
-(async () => {
-    await connectDb();
-
-    console.log("Checking Certificate Expiry Date");
-
-    // TODO: Query monitor_tls_info
-
-    exit();
-})();
diff --git a/server/model/monitor.js b/server/model/monitor.js
index 2f28e5b9..01d0a1f5 100644
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@@ -168,7 +168,14 @@ class Monitor extends BeanModel {
                     let certInfoStartTime = dayjs().valueOf();
                     if (this.getUrl()?.protocol === "https:") {
                         try {
-                            tlsInfo = await this.updateTlsInfo(checkCertificate(res));
+                            let tlsInfoObject = checkCertificate(res);
+                            tlsInfo = await this.updateTlsInfo(tlsInfoObject);
+
+                            if (!this.getIgnoreTls()) {
+                                debug("call sendCertNotification");
+                                await this.sendCertNotification(tlsInfoObject);
+                            }
+
                         } catch (e) {
                             if (e.message !== "No TLS certificate in response") {
                                 console.error(e.message);
@@ -595,9 +602,7 @@ class Monitor extends BeanModel {
 
     static async sendNotification(isFirstBeat, monitor, bean) {
         if (!isFirstBeat || bean.status === DOWN) {
-            let notificationList = await R.getAll("SELECT notification.* FROM notification, monitor_notification WHERE monitor_id = ? AND monitor_notification.notification_id = notification.id ", [
-                monitor.id,
-            ]);
+            const notificationList = await Monitor.getNotificationList(monitor);
 
             let text;
             if (bean.status === UP) {
@@ -619,6 +624,70 @@ class Monitor extends BeanModel {
         }
     }
 
+    static async getNotificationList(monitor) {
+        let notificationList = await R.getAll("SELECT notification.* FROM notification, monitor_notification WHERE monitor_id = ? AND monitor_notification.notification_id = notification.id ", [
+            monitor.id,
+        ]);
+        return notificationList;
+    }
+
+    async sendCertNotification(tlsInfoObject) {
+        if (tlsInfoObject && tlsInfoObject.certInfo && tlsInfoObject.certInfo.daysRemaining) {
+            const notificationList = await Monitor.getNotificationList(this);
+
+            debug("call sendCertNotificationByTargetDays");
+            await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 21, notificationList);
+            await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 14, notificationList);
+            await this.sendCertNotificationByTargetDays(tlsInfoObject.certInfo.daysRemaining, 7, notificationList);
+        }
+    }
+
+    async sendCertNotificationByTargetDays(daysRemaining, targetDays, notificationList) {
+
+        if (daysRemaining > targetDays) {
+            debug(`No need to send cert notification. ${daysRemaining} > ${targetDays}`);
+            return;
+        }
+
+        if (notificationList.length > 0) {
+
+            let row = await R.getRow("SELECT * FROM notification_sent_history WHERE type = ? AND monitor_id = ? AND days = ?", [
+                "certificate",
+                this.id,
+                targetDays,
+            ]);
+
+            // Sent already, no need to send again
+            if (row) {
+                debug("Sent already, no need to send again");
+                return;
+            }
+
+            let sent = false;
+            debug("Send certificate notification");
+
+            for (let notification of notificationList) {
+                try {
+                    debug("Sending to " + notification.name);
+                    await Notification.send(JSON.parse(notification.config), `The certificate of ${this.url} will be expired in ${daysRemaining} days`);
+                    sent = true;
+                } catch (e) {
+                    console.error("Cannot send cert notification to " + notification.name);
+                    console.error(e);
+                }
+            }
+
+            if (sent) {
+                await R.exec("INSERT INTO notification_sent_history (type, monitor_id, days) VALUES(?, ?, ?)", [
+                    "certificate",
+                    this.id,
+                    targetDays,
+                ]);
+            }
+        } else {
+            debug("No notification, no need to send cert notification");
+        }
+    }
 }
 
 module.exports = Monitor;