How do you handle date, time, and number formats in UI?

1 Why is i18n important in UI?

Internationalization is the process of making your UI ready for localization (l10n), which is the adaptation of your UI to a specific language, culture, or region. By internationalizing your UI, you can ensure that it can support multiple languages, formats, and preferences without requiring major changes or redesigns. This can help you reach a wider and more diverse audience, improve user satisfaction and retention, and avoid potential legal or regulatory issues.

2 How to handle date formats in UI?

Date formats vary significantly across the world, and using the wrong format can lead to errors or confusion. To avoid this, you should use ISO 8601 as the default date format for internal data storage and exchange, which follows the order YYYY-MM-DD (e.g., 2021-02-01). Additionally, you should use locale-specific date formats for displaying dates to users, taking into consideration the appropriate separators, order, and components (e.g., day, month, year, weekday, era). You can use libraries or frameworks that provide locale-aware date formatting functions. Furthermore, it's beneficial to provide users with the option to customize their date format preferences, such as choosing between short, medium, long, or full formats, or switching between 12-hour and 24-hour clocks.

3 How to handle time formats in UI?

Time formats differ across the world and using the wrong format can cause confusion or inconvenience. To avoid this, you should use UTC (Coordinated Universal Time) as the default time format for internal data storage and exchange. This is a standard format that uses the 24-hour clock and is independent of any time zone or daylight saving time. For displaying times to users, you should use locale-specific time formats, such as Intl.DateTimeFormat in JavaScript or DateFormat in Java. Additionally, you should provide users with options to customize their time format preferences, like choosing between 12-hour and 24-hour clocks, or selecting their preferred time zone or daylight saving time.

4 How to handle number formats in UI?

Using the wrong number format can lead to errors or misinterpretations, as different countries use a comma or dot as a decimal separator, and different grouping separators, symbols, or units for large numbers, currencies, percentages, or fractions. To avoid this, you should use a standard number format for internal data storage and exchange (e.g., 1234.56), and locale-specific number formats for displaying numbers to users. Libraries or frameworks that provide locale-aware number formatting functions, such as Intl.NumberFormat in JavaScript or NumberFormat in Java, can help with this. Additionally, it's wise to provide users with the option to customize their number format preferences.

5 What tools and standards can help with i18n in UI?

Internationalization (i18n) of user interface (UI) can be managed with a variety of tools and standards. Unicode is a universal standard for encoding and representing text in different languages and scripts, covering over 140,000 characters from more than 150 scripts and languages. It also supports bidirectional text, diacritics, ligatures, and emoji. The Unicode standard should be used as the default encoding for UI text and data. Common Locale Data Repository (CLDR) is a repository of locale data providing information on date, time, number, currency, and other formats for over 500 locales. It also provides translations for common UI elements such as labels, buttons, menus, and messages. International Components for Unicode (ICU) is a library that provides comprehensive and consistent support for i18n and l10n in various programming languages and platforms. It includes functions for formatting, parsing, sorting, searching, and manipulating text, dates, times, numbers, currencies, and other data types according to locale rules and preferences. ICU can be used as a dependency or as a standalone tool for UI development.

6 How to test and evaluate your i18n in UI?

Testing and evaluating your i18n in UI is a necessary step to guarantee that your UI functions properly and meets the expectations of your users. Pseudolocalization should be used to simulate different languages and scripts in your UI, which can help identify and fix layout, alignment, truncation, overflow, font, or encoding problems. Localization testing should be done to verify the quality and accuracy of translations and adaptations in your UI. This process involves checking for linguistic, cultural, functional, and technical errors or inconsistencies in different locales. User testing should also be done to evaluate the usability and satisfaction of your UI in different locales. This process involves collecting feedback from real or representative users who interact with your UI in their native language and context. Surveys, interviews, observations, or analytics can be used for this task.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?