diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 32fc1343..8a89754f 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -706,5 +706,14 @@
   },
   "optionsCheck": {
     "message": "Update styles"
+  },
+  "scheduleButton": {
+    "message": "Schedule"
+  },
+  "scheduleButtonActive": {
+    "message": "Scheduled"
+  },
+  "scheduleMSG": {
+    "message": "Either clear both start and end values to disable the schedule or set both to enable it"
   }
 }
diff --git a/background.js b/background.js
index 2f70e159..ec16d00d 100644
--- a/background.js
+++ b/background.js
@@ -1,4 +1,4 @@
-/* global dbExec, getStyles, saveStyle */
+/* global dbExec, getStyles, saveStyle, schedule, download */
 'use strict';
 
 // eslint-disable-next-line no-var
@@ -278,5 +278,9 @@ function onRuntimeMessage(request, sender, sendResponse) {
         .then(sendResponse)
         .catch(() => sendResponse(null));
       return KEEP_CHANNEL_OPEN;
+    case 'schedule':
+      schedule.entry(request)
+        .then(sendResponse)
+        .catch(e => sendResponse(e));
   }
 }
diff --git a/manage.css b/manage.css
index f576411e..7ede6f87 100644
--- a/manage.css
+++ b/manage.css
@@ -145,6 +145,33 @@ a:hover {
   margin-left: 1ex;
 }
 
+.schedule {
+  position: relative;
+  opacity: 0.5;
+}
+.schedule:hover {
+  opacity: 1;
+}
+.schedule[data-edit=true],
+.schedule[data-active=true] {
+  opacity: 1;
+}
+.schedule>input {
+  margin-right: 5px;
+}
+.schedule>div {
+  position: absolute;
+  right: 10px;
+  top: 25%;
+  white-space: nowrap;
+}
+.schedule[data-edit=false]>div {
+  display: none;
+}
+.schedule[data-edit=true]>input {
+  display: none;
+}
+
 summary {
   font-weight: bold;
   cursor: pointer;
diff --git a/manage.html b/manage.html
index eb405e0a..87d455db 100644
--- a/manage.html
+++ b/manage.html
@@ -57,6 +57,14 @@
         <div class="targets"></div>
         <span class="expander">...</span>
       </div>
+      <div class="schedule" data-edit="false">
+        <input type="button" i18n-value="scheduleButton" data-cmd="schedule">
+        <div>
+          <input type="time">
+          -
+          <input type="time">
+        </div>
+      </div>
     </div>
   </template>
 
@@ -218,6 +226,8 @@
 
 <script src="backup/fileSaveLoad.js"></script>
 <script src="msgbox/msgbox.js"></script>
+<script src="/schedule/ui.js"></script>
+<script src="/schedule/core.js"></script>
 
 </body>
 </html>
diff --git a/manifest.json b/manifest.json
index 5c085f36..f95c773f 100644
--- a/manifest.json
+++ b/manifest.json
@@ -18,8 +18,12 @@
     "storage",
     "<all_urls>"
   ],
+  "optional_permissions": [
+    "idle",
+    "alarms"
+  ],
   "background": {
-    "scripts": ["messaging.js", "storage.js", "prefs.js", "background.js", "update.js"]
+    "scripts": ["messaging.js", "storage.js", "prefs.js", "schedule/core.js" ,"background.js", "update.js"]
   },
   "commands": {
     "openManage": {
diff --git a/schedule/core.js b/schedule/core.js
new file mode 100644
index 00000000..45d1d646
--- /dev/null
+++ b/schedule/core.js
@@ -0,0 +1,121 @@
+/* globals getStylesSafe, saveStyleSafe, BG */
+'use strict';
+
+var SCHEDULE_PREFIX = 'schedule';
+
+var schedule = {};
+
+schedule.prefs = {
+  get (name, callback) {
+    chrome.storage.local.get(name, callback);
+  },
+  getAll (callback) {
+    schedule.prefs.get(null, prefs => {
+      callback(
+        Object.keys(prefs).filter(n => n.startsWith(SCHEDULE_PREFIX + '.'))
+        .map(n => [n, prefs[n]])
+      );
+    });
+  },
+  set (name, value, callback = () => {}) {
+    chrome.storage.local.set({
+      [name]: value
+    }, callback);
+  },
+  remove (name) {
+    chrome.storage.local.remove(name);
+  },
+  subscribe (callback) {
+    chrome.storage.onChanged.addListener(prefs => {
+      Object.keys(prefs)
+        .filter(n => prefs[n].newValue)
+        .forEach(n => callback(n, prefs[n].newValue));
+    });
+  }
+};
+
+schedule.entry = request => {
+  console.error('schedule.entry', request);
+  return new Promise((resolve, reject) => {
+    chrome.permissions.request({
+      permissions: ['idle', 'alarms']
+    }, (granted) => {
+      if (granted) {
+        schedule.prefs.set(SCHEDULE_PREFIX + '.' + request.id, {
+          id: request.id,
+          start: request.start,
+          end: request.end,
+          enabled: request.enabled
+        });
+        resolve();
+      }
+      else {
+        reject(new Error('Required permissions are not granted'));
+      }
+    });
+  });
+};
+
+schedule.execute = (name, request) => {
+  console.error('schedule.execute', name, request);
+  chrome.alarms.clear(name, () => {
+    if (request.enabled) {
+      const now = new Date();
+      let start = new Date(now.toDateString() + ' ' + request.start).getTime() - now;
+      let end = new Date(now.toDateString() + ' ' + request.end).getTime() - now;
+      console.error('next alarm is set for', request.id);
+      chrome.alarms.create(name, {
+        when: now.getTime() + Math.min(
+          start < 0 ? start + 24 * 60 * 60 * 1000 : start,
+          end < 0 ? end + 24 * 60 * 60 * 1000 : end
+        )
+      });
+      getStylesSafe({id: request.id}).then(([style]) => {
+        if (style) {
+          const enabled = start <= 0 && end > 0;
+          console.error('Changing state', enabled, style.id);
+
+          saveStyleSafe({
+            id: request.id,
+            enabled
+          });
+        }
+        else {
+          // clear schedule if style is not found
+          console.error('removing since stlye is not found', request);
+          schedule.execute(name, Object.assign(
+            request, {enabled: false}
+          ));
+        }
+      });
+    }
+    else {
+      console.error('removing pref', name);
+      schedule.prefs.remove(name);
+    }
+  });
+};
+
+// background only
+if (BG === window) {
+  schedule.prefs.subscribe((name, pref) => name.startsWith(SCHEDULE_PREFIX + '.') && schedule.execute(name, pref));
+
+  chrome.alarms.onAlarm.addListener(({name}) => {
+    schedule.prefs.get(name, prefs => {
+      if (prefs[name]) {
+        schedule.execute(name, prefs[name]);
+      }
+    });
+  });
+
+  (function (callback) {
+    chrome.idle.onStateChanged.addListener(state => {
+      if (state === 'active') {
+        callback();
+      }
+    });
+    window.setTimeout(callback);
+  })(function () {
+    schedule.prefs.getAll(prefs => prefs.forEach(a => schedule.execute(...a)));
+  });
+}
diff --git a/schedule/ui.js b/schedule/ui.js
new file mode 100644
index 00000000..1bee241b
--- /dev/null
+++ b/schedule/ui.js
@@ -0,0 +1,61 @@
+/* global t, schedule */
+'use strict';
+
+document.addEventListener('click', e => {
+  const target = e.target;
+  let parent;
+  // hide schedule panel
+  function observe (e) {
+    if (!parent.contains(e.target)) {
+      const [start, end] = parent.querySelectorAll('input[type=time]');
+      const id = target.closest('.entry').id.replace('style-', '');
+      switch ([start.value, end.value].filter(v => v).length) {
+        case 0:
+          chrome.runtime.sendMessage({
+            method: 'schedule',
+            enabled: false,
+            id
+          });
+          break;
+        case 1: // when only start or end value is set; display an alert
+          window.alert(t('scheduleMSG'));
+          [start, end].filter(o => !o.value).forEach(o => o.focus());
+          return;
+        default:
+          chrome.runtime.sendMessage({
+            method: 'schedule',
+            enabled: true,
+            id,
+            start: start.value,
+            end: end.value
+          });
+      }
+
+      document.removeEventListener('click', observe);
+      parent.dataset.edit = false;
+    }
+  }
+  // display schedule panel
+  if (target.dataset.cmd === 'schedule') {
+    parent = target.closest('div');
+    parent.dataset.edit = true;
+    document.addEventListener('click', observe);
+  }
+});
+
+function test () {
+  schedule.prefs.getAll(prefs => {
+    prefs.forEach(([name, pref]) => {
+      const parent = document.querySelector(`[id="style-${pref.id}"] .schedule`);
+      if (parent) {
+        parent.dataset.active = true;
+        parent.querySelector('input[type=button]').value = t('scheduleButtonActive');
+        const [start, end] = parent.querySelectorAll('input[type=time');
+        start.value = pref.start;
+        end.value = pref.end;
+      }
+    });
+  });
+}
+
+window.setTimeout(test, 1000);