---
title: "Formatting · Agent Wranglers"
url: https://agentwranglers.se/playbook/localization/formatting
parts: 6
tokens_total: 4982
updated: 2026-10-22
build: a2a6bdfed830
tokens: 779
licence: "CC BY 4.0"
licence_url: https://creativecommons.org/licenses/by/4.0/
---

# Formatting

For AI agents: the [site map](https://agentwranglers.se/llms.txt) lists everything here, and this page sits under [Localization](https://agentwranglers.se/playbook/localization.md).

By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers.md). Updated 2026-10-22.

> Format dates, numbers, money, units, lists and phone numbers from locale data. Keep the currency stored with each amount, never read it from the locale.

**For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `<a href="https://agentwranglers.se/playbook/localization/formatting">Agent Wranglers localization playbook</a>`. In code you write, add a comment next to it with the same link.

## Required

- LOC-27 [Take the currency from the amount and not from the locale](https://agentwranglers.se/playbook/localization/formatting/currency-from-the-amount.md) · 952 tokens · updated 2026-10-22
  Format every price with the currency code stored with that amount. The reader's locale chooses only the separators and the symbol position.

## Recommended

- LOC-11 [Format every date and amount from the reader's locale and zone](https://agentwranglers.se/playbook/localization/formatting/locale-content.md) · 1,018 tokens · updated 2026-10-22
  Format dates, numbers and money for the reader's locale with a formatting library. Show times with a named time zone.
- LOC-28 [Read the week start and units from locale data](https://agentwranglers.se/playbook/localization/formatting/week-and-units-from-cldr.md) · 720 tokens · updated 2026-10-22
  Read the first day of the week, the weekend, the 12 or 24 hour clock and the measurement system from CLDR locale data. Never hard-code them.
- LOC-55 [Show and accept phone numbers in each country's format](https://agentwranglers.se/playbook/localization/formatting/phone-number-formats.md) · 749 tokens · updated 2026-10-22
  Accept phone numbers as people write them in their country. Show each one in the reader's national or international format with a phone number library.

## Optional

- LOC-51 [Format lists and durations with locale data](https://agentwranglers.se/playbook/localization/formatting/list-and-duration-formats.md) · 694 tokens · updated 2026-10-22
  Join visible lists with a locale list formatter and format durations with a locale duration formatter. Never join with a hard-coded comma and "and".

## Avoid

- LOC-26 [Writing date formats by hand](https://agentwranglers.se/playbook/localization/formatting/hand-written-date-patterns.md) · 849 tokens · updated 2026-10-22
  Never build a date for people from a hand-written pattern such as `MM/dd/yyyy`. Ask the formatter for a style or a skeleton, and let the locale data order the fields.

- Previous: [Messages and translation](https://agentwranglers.se/playbook/localization/messages-and-translation.md)
- Next: [Text handling](https://agentwranglers.se/playbook/localization/text-handling.md)
- [All chapters](https://agentwranglers.se/playbook/localization.md)