Countdown Timer
A live countdown to a deadline that ends cleanly instead of running negative.
What it adds
A countdown component driven by a server-provided deadline, with a defined finished state.
What your agent is told to do
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What your agent is told to do
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Send the deadline and the server's current time together, compute the offset between server and device once, and count against the corrected value. The device clock cannot be trusted to be right.
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Recompute the remaining time from the corrected clock on every tick rather than decrementing a stored number, so a suspended tab does not resume showing a value minutes behind reality.
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Define the finished state explicitly: what the component shows at zero, whether it reveals something, disables a control, or triggers a refetch. Reuse the app's existing Progress Indicator System styling rather than introducing new type and colour for the digits.
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Reserve the widest layout the digits will ever occupy so the surrounding content does not shift as the count crosses from two digits to one, or drops the hours segment.
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Do not treat the client countdown as enforcement. Whatever the deadline gates must be checked again on the server, because anyone can change their clock or edit the displayed value.
Edge cases it handles
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Edge cases it handles
8- A backgrounded or sleeping tab stops receiving ticks. On becoming visible again, recompute from the corrected clock and render the true remaining time rather than continuing from where the timer paused.
- The device clock may be wrong by hours or set deliberately. Anchor to a server timestamp delivered with the page and treat the device only as a source of elapsed time since that anchor.
- A countdown that reaches zero must switch to its finished state, not continue into negative numbers. Decide what happens at zero before building the counting.
- Announcing every second to a screen reader is unusable. Give the timer an accessible label with the remaining time and announce only at meaningful intervals, such as at the last few minutes and at zero.
- Stop the tick when the component is offscreen or the tab is hidden, and under prefers-reduced-motion render a static remaining time updated infrequently instead of a live ticking display.
- A deadline already in the past when the page loads must render finished immediately, with no flash of a large positive number.
- The unit labels and number formatting must follow the viewer's locale, and the largest unit should drop away as it empties rather than showing a leading zero for days.
- Multiple countdowns on one page should share a single tick rather than each running their own interval.
Definition of done
9
Definition of done
9- The countdown is anchored to a server timestamp and is unaffected by a wrong device clock.
- Returning to a backgrounded tab shows the correct remaining time immediately.
- Reaching zero switches to a defined finished state and never displays negative time.
- A deadline already past renders finished on first paint with no flash.
- Ticking stops when the component is hidden and is suppressed under prefers-reduced-motion.
- Remaining time is available to screen readers without per-second announcements.
- The digits occupy reserved space and the layout does not shift as units change.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Beautiful Empty States
Beautiful Empty States
Replace blank screens with useful, contextual empty states.
What it does
Every list, table, and dashboard in your app has a "nothing here yet" state. Most
apps ship a blank rectangle — and it is often the very first thing a new user sees.
An empty state should say what belongs here, why it is empty, and what to do next.
How it works
- 1 Inventory the empty cases first. List every collection view in the app and
- 2 Distinguish the three kinds of empty. They are not the same, and must not
- 3 Build one reusable empty-state component from the existing design system,
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/beautiful-empty-states
Media Aspect Ratio System
Media Aspect Ratio System
Give every thumbnail, avatar, and hero a shared, reserved shape so nothing jumps.
What it does
A small set of named aspect ratios applied to every image and video surface, with reserved space, a defined fit, and a defined fallback.
How it works
- 1 Catalogue the media surfaces already in the app — list thumbnails, card covers, avatars, hero banners, video embeds, attachment previews — and reduce them to a handful of named ratios rather than a per-component value.
- 2 Reserve the box before the media loads so the ratio holds space from first paint. Layout that settles after an image arrives moves whatever the user was about to click.
- 3 Set the fit per content type, not per component: faces and product shots crop to fill from a sensible focal point, diagrams and screenshots fit whole with padding, because cropping a diagram loses the content it exists to show.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/media-aspect-ratio-system
Opening Hours Display
Opening Hours Display
Say whether you are open right now and when you next open.
What it does
A live open or closed state alongside the weekly hours, with holiday closures folded in.
How it works
- 1 Lead with the current state in plain words and follow it with the next transition: open until a time, or closed until a day and time. The weekly table is supporting detail, not the headline.
- 2 Store hours as intervals against the business's own zone, and keep holiday and one-off closures as overrides that win over the regular week rather than as edits to it.
- 3 Compute the state on the server for the first render so the page does not briefly claim the wrong thing, then let the page update itself as the clock crosses a boundary without a reload.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/opening-hours-display
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.