Time Zone-Aware Scheduling
Schedule things for the right local time when everyone is in a different zone.
What it adds
Scheduling that stores an unambiguous instant alongside the intended zone, and survives daylight-saving transitions.
What your agent is told to do
5
What your agent is told to do
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Store both the resolved instant and the IANA zone identifier the user chose. The instant alone loses the intent; the local time alone is ambiguous.
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Show the user the zone their schedule is in, and show viewers in other zones the same moment converted to theirs with the zone named.
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Decide per schedule type whether it is a fixed instant or a recurring local wall-clock time, and store that intent explicitly — the two diverge every time the clocks change.
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Resolve daylight-saving edge cases with a stated rule: a nonexistent local time and a repeated local time both need a defined answer, not whatever the library defaults to.
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Do NOT store a UTC offset in place of a zone name. Offsets go stale the moment the rules change, and governments change them.
Edge cases it handles
6
Edge cases it handles
6- A local time that does not exist during a spring-forward gap must be shifted by a documented rule and shown to the user.
- A repeated local time in an autumn-back overlap must pick one occurrence deliberately.
- Existing schedules must not shift when a country changes its time-zone rules — historical instants stay fixed.
- A recurring 9am local schedule must remain 9am local across a DST change, which means its UTC time moves.
- The browser-detected zone is a default, not a decision — let the user change it.
- Sends near a transition must not fire twice or be skipped.
Definition of done
8
Definition of done
8- Every schedule stores an instant plus an IANA zone identifier.
- Fixed-instant and recurring-local schedules are distinguishable in the data.
- Times are displayed in the viewer's zone with the zone named.
- Nonexistent and ambiguous local times resolve by a documented rule.
- A DST transition does not duplicate or skip a scheduled run.
- Time-zone rule updates do not move existing scheduled instants.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Unit Converter
Unit Converter
Let people convert a value between units without leaving the page they are on.
What it does
An inline converter that takes a typed value in one unit and shows the equivalent in another, in place.
How it works
- 1 Start from the units the app actually deals in. A shipping tool needs weight and length; a recipe tool needs volume and temperature. Ship those and leave the rest out.
- 2 Convert as the user types, with the result visible beside the input rather than behind a submit button. Let either side be edited so the conversion runs in both directions.
- 3 Reuse the app's existing number parsing and display formatting rather than writing new ones. If Locale-Aware Numbers and Dates or Number Formatting Component is already present, the converter must render through it so grouping and decimal marks match the rest of the app.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/unit-converter
Voice Dictation
Voice Dictation
Put a microphone in text fields so people can speak their input instead of typing it.
What it does
A dictation control on the app's longer text inputs that transcribes speech into the field as the user talks.
How it works
- 1 Add the control to the fields where typing is genuinely tedious: long descriptions, notes, comments, and message bodies. A microphone on a postcode field is clutter.
- 2 Show interim results in the field as they arrive, visually distinct from committed text, so the speaker can see it is working and correct course before they finish.
- 3 Reuse the app's existing Voice Transcription for the server-side path so one recognition configuration and one set of language settings serve both dictation and recorded audio.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/voice-dictation
Code Editor Field
Code Editor Field
Edit code, JSON, and config with syntax highlighting instead of a bare textarea.
What it does
A form field backed by a real code editor: syntax highlighting, a language mode per field, and inline validation that tolerates work in progress.
How it works
- 1 Load the editor library lazily, only on views that use it, and render a usable plain textarea until it arrives. It must never block first paint.
- 2 Set the language mode per field from what the field actually holds, and validate against that mode.
- 3 Report syntax errors as you go, but never block typing or reset the content. Half-written JSON is a normal intermediate state; only submission should be gated.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/code-editor-field
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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3
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.