Chrome-Extensions

Countdown Timer Chrome Extension

A simple, private Chrome extension for tracking important dates. It keeps your countdowns available after the popup closes and notifies you when each one finishes.

Install CountDown Timer from the Chrome Web Store

Features

• Create, edit, reset, and delete multiple titled countdowns with compact, labelled icon controls.
• Review an inline confirmation before deleting a countdown.
• Organize timers with optional work, personal, celebration, travel, and important labels.
• Live days, hours, minutes, and seconds display, sorted by the nearest upcoming event.
• A completion notification for each timer, even when the extension popup is closed; notifications use the timer label and varied reminder text.
• Timers persist across Chrome restarts.
• Stores timer data only in local Chrome extension storage.

Install locally

1. Download or clone this repository.
2. In Chrome, open chrome://extensions.
3. Enable Developer mode.
4. Select Load unpacked.
5. Choose the Date_Countdown folder.
6. Pin CountDown Timer from the Chrome extensions menu, then open it to create a timer.

Project structure

Date_Countdown/
  manifest.json          Chrome extension manifest (Manifest V3)
  Counter.html           Extension popup
  css/style.css          Popup styles
  js/countdown.js        Popup and countdown behavior
  js/background.js       Alarm scheduling and notifications

Permissions

The extension requests:

• storage to save the timer locally.
• alarms to schedule the completion event.
• notifications to notify you when the countdown completes.

Chrome extension approach

• Built on Manifest V3 with an event-driven service worker.
• Uses only the minimum required permissions; it does not request access to websites or browsing data.
• Schedules each completion with Chrome’s alarms API and restores alarms when Chrome starts.
• Keeps all data local and does not load remote code, scripts, or assets.
• Includes keyboard focus states, semantic controls, and live status messages.

Privacy policy

Last updated: July 11, 2026

Countdown Timer stores the title, label, date/time, and completion-notification status of each timer you create. It also stores the last notification-template choice so consecutive completion reminders use different wording. This information is stored only in Chrome’s local extension storage on your device so timers can continue and notify you when the popup is closed.

The extension does not collect, transmit, sell, share, or use this information for advertising, analytics, profiling, or any purpose other than providing the timer and its notification. It does not access browsing history, web page content, accounts, or location data.

You can remove stored timer information at any time using the Delete icon on a countdown and confirming the action.

For support, open an issue in the GitHub repository.

For a direct link to this policy, use the privacy policy section.

Development

After changing extension files, return to chrome://extensions and click the reload button on the CountDown Timer card. Reopen the popup to test the update.

License

No license has been specified for this repository.

See ATTRIBUTIONS.md for third-party icon notices.