diff --git a/www/common/cryptpad-common.js b/www/common/cryptpad-common.js
index b639eebab..51ec09ef6 100644
--- a/www/common/cryptpad-common.js
+++ b/www/common/cryptpad-common.js
@@ -2288,7 +2288,8 @@ define([
                 cache: rdyCfg.cache,
                 noDrive: rdyCfg.noDrive,
                 disableCache: localStorage['CRYPTPAD_STORE|disableCache'],
-                driveEvents: !rdyCfg.noDrive //rdyCfg.driveEvents // Boolean
+                driveEvents: !rdyCfg.noDrive, //rdyCfg.driveEvents // Boolean
+                lastVisit: Number(localStorage.lastVisit) || undefined
             };
             common.userHash = userHash;
 
@@ -2570,6 +2571,12 @@ define([
                 AppConfig.afterLogin(common, waitFor());
             }
         }).nThen(function () {
+            // Last visit is used to warn you about missed events from your calendars
+            localStorage.lastVisit = +new Date();
+            setInterval(function () {
+                // Bump last visit every minute
+                localStorage.lastVisit = +new Date();
+            }, 60000);
             f(void 0, env);
             if (typeof(window.onhashchange) === 'function') { window.onhashchange(); }
         });
diff --git a/www/common/notifications.js b/www/common/notifications.js
index 018093c2a..35ebb447c 100644
--- a/www/common/notifications.js
+++ b/www/common/notifications.js
@@ -459,19 +459,37 @@ define([
         }
     };
 
+    Messages.reminder_missed = "You missed <b>{0}</b> on {1}"; // XXX
+    Messages.reminder_inProgress = "<b>{0}</b> has started on {1}"; // XXX
+    Messages.reminder_inProgressAllDay = "<b>{0}</b> is happening today"; // XXX
     Messages.reminder_minutes = "<b>{0}</b> will start in {1} minutes!"; // XXX
     Messages.reminder_hour = "<b>{0}</b> will start in 1 hour!"; // XXX
     handlers['REMINDER'] = function (common, data) {
         var content = data.content;
         var msg = content.msg.content;
+        var missed = content.msg.missed;
         var now = +new Date();
         var start = msg.start;
+        var title = Util.fixHTML(msg.title);
         content.getFormatText = function () {
+            // Missed events
+            if (start < now && missed) {
+                return Messages._getKey('reminder_missed', [title, new Date(start).toLocaleString()]);
+            }
+            // In progress, is all day
+            if (start < now && msg.isAllDay) {
+                return Messages._getKey('reminder_inProgressAllDay', [title]);
+            }
+            // In progress, normal event
+            if (start < now) {
+                return Messages._getKey('reminder_inProgress', [title, new Date(start).toLocaleString()]);
+            }
+            // Not started yet
             if ((start - now) > 600000) {
-                return Messages._getKey('reminder_hour', [Util.fixHTML(msg.title)]);
+                return Messages._getKey('reminder_hour', [title]);
             }
             var minutes = Math.round((start - now) / 60000);
-            return Messages._getKey('reminder_minutes', [Util.fixHTML(msg.title), minutes]);
+            return Messages._getKey('reminder_minutes', [title, minutes]);
         };
         if (!content.archived) {
             content.dismissHandler = defaultDismiss(common, data);
diff --git a/www/common/outer/calendar.js b/www/common/outer/calendar.js
index 016e95abb..2113dcc69 100644
--- a/www/common/outer/calendar.js
+++ b/www/common/outer/calendar.js
@@ -90,31 +90,43 @@ define([
         });
     };
 
-    var updateEventReminders = function (ctx, reminders, ev) {
+    var updateEventReminders = function (ctx, reminders, ev, useLastVisit) {
         var now = +new Date();
         var time10 = now + (600 * 1000); // 10 minutes from now
         var time60 = now + (3600 * 1000); // 1 hour from now
         var uid = ev.id;
 
+        ctx.store.data.lastVisit = 1617922639683; // XXX Friday Apr 09
+
         // Clear reminders for this event
         if (Array.isArray(reminders[uid])) {
             reminders[uid].forEach(function (to) { clearTimeout(to); });
         }
         reminders[uid] = [];
 
-        // No reminder for past events
-        if (ev.start <= now) {
+        var last = ctx.store.data.lastVisit;
+        // XXX add a limit to make sure we don't go too far in the past?
+        var missed = useLastVisit && ev.start > last && ev.end <= now;
+        if (ev.end <= now && !missed) {
+            // No reminder for past events
             delete reminders[uid];
             return;
         }
 
+        // XXX
+        // TODO
+        // use custom notifications per event
+        // if you missed a notification, show it instantly (eg: load cryptpad 45min before an event, show the 1h notification)
+
         var send = function () {
             var hide = Util.find(ctx, ['store', 'proxy', 'settings', 'general', 'calendar', 'hideNotif']);
             if (hide) { return; }
+            var ctime = ev.start <= now ? ev.start : +new Date(); // Correct order for past events
             ctx.store.mailbox.showMessage('reminders', {
                 msg: {
-                    ctime: +new Date(),
+                    ctime: ctime,
                     type: "REMINDER",
+                    missed: Boolean(missed),
                     content: ev
                 },
                 hash: 'REMINDER|'+uid
@@ -152,7 +164,7 @@ define([
 
         updateEventReminders(ctx, calendar.reminders, ev);
     };
-    var addInitialReminders = function (ctx, id) {
+    var addInitialReminders = function (ctx, id, useLastVisit) {
         var calendar = ctx.calendars[id];
         if (!calendar || !calendar.reminders) { return; }
         if (Object.keys(calendar.reminders).length) { return; } // Already initialized
@@ -164,7 +176,7 @@ define([
         var content = Util.find(calendar, ['proxy', 'content']);
         if (!content) { return; }
         Object.keys(content).forEach(function (uid) {
-            updateEventReminders(ctx, calendar.reminders, content[uid]);
+            updateEventReminders(ctx, calendar.reminders, content[uid], useLastVisit);
         });
     };
     var openChannel = function (ctx, cfg, _cb) {
@@ -325,7 +337,7 @@ define([
                 c.cacheready = true;
                 setTimeout(update);
                 if (cb) { cb(null, lm.proxy); }
-                addInitialReminders(ctx, channel);
+                addInitialReminders(ctx, channel, cfg.lastVisitNotif);
             }).on('ready', function (info) {
                 var md = info.metadata;
                 c.owners = md.owners || [];
@@ -342,7 +354,7 @@ define([
                 }
                 setTimeout(update);
                 if (cb) { cb(null, lm.proxy); }
-                addInitialReminders(ctx, channel);
+                addInitialReminders(ctx, channel, cfg.lastVisitNotif);
             }).on('change', [], function () {
                 if (!c.ready) { return; }
                 setTimeout(update);
@@ -455,6 +467,7 @@ define([
             decryptTeamCalendarHref(store, cal);
             openChannel(ctx, {
                 storeId: storeId,
+                lastVisitNotif: true,
                 data: cal
             });
         });