Intl DateTime Calendar

Changelog

2.0.2

• Fix: The preview on the settings page showed dates in your own admin language rather than the language your visitors read. On a site whose language differs from the editor’s, it previewed months no visitor would ever see
• Improvement: The preview now names the language it is showing, so there is no doubt which one it means

2.0.1

Fixes a fatal error that could take the front end down after switching the site language.

• Fix: Switching the site to a language ICU has no data for, such as South Azerbaijani, Saraiki, Hazaragi or Northern Kurdish, brought down the front end with a critical error. Those languages now keep the dates WordPress itself produces, which are already translated
• Fix: A failed date formatter is no longer reused for the rest of the request, so one bad locale cannot repeat the failure on every date
• Fix: A site with no language set no longer builds an invalid locale
• Fix: A language with a region ICU does not carry now falls back to the language rather than giving up
• Fix: Formatting can no longer raise out of the plugin at all. A date that cannot be converted is left as WordPress wrote it

2.0.0

This release rebuilds how dates are formatted. Sites using the Gregorian calendar see no change at all. We check this automatically against PHP’s own date function on every commit.

New:

• Dates are now written on the server where the PHP intl extension is available. There is no longer a flash of Gregorian dates while the page loads. Dates are correct without JavaScript.
• Added a choice of digits covering every decimal numbering system Unicode defines. Thai, Arabic, Persian, Bengali, Devanagari, Khmer and many other sites can use their own numerals.
• Relative dates such as “3 days ago” are now translated instead of being left in English
• Added the intl_datetime_calendar_format_date() function, which the FAQ has described since 1.0.2 but which was never actually included
• Added a Site Health check reporting whether dates are converted on the server or in the browser
• Added the intl_datetime_calendar_calendar, intl_datetime_calendar_locale, intl_datetime_calendar_numbering_system and intl_datetime_calendar_should_convert filters
• Different languages can now use different calendars on a multilingual site
• Removing the plugin now cleans up its settings

Fixed:

• Dates from the shortcode were up to a day out on any site not set to UTC. They published a timezone offset that did not match the time beside it.
• Custom date formats were ignored. A format of Y-m-d and a format of d/m/Y both produced the same output, and any text or separator in a format was discarded
• A 12 hour format such as h:i A produced output like 08 PM:5 PM
• Minutes and seconds lost their leading zero, so five past showed as 5 rather than 05
• Buddhist and Hijri dates leaked an era marker into numeric formats, giving 04/05/พ.ศ. 2568 instead of 04/05/2568
• Custom block formats were silently dropped for dates inside a Query Loop
• Impossible dates such as 31 February were quietly changed to a real date instead of being reported
• A date of 1 January 1970 was treated as invalid
• Month names now take the correct grammatical form in Russian, Czech, Polish, Catalan and other languages that inflect them
• Rendering could stop the page with a fatal error on a server without PHP’s DOM extension
• Block markup containing <picture> or <source> could be corrupted while dates were being processed
• Three of the four block filters had never run, because the blocks they named do not exist in WordPress

Changed:

• Requires PHP 8.1 and WordPress 6.5
• Block markup is now edited with WordPress’s own HTML API instead of a regular expression and an HTML4 parser
• The settings page no longer uses an inline script
• The browser script is only loaded when the server cannot convert dates itself
• The minified script is now generated by a build step and checked automatically, instead of being maintained by hand

1.0.3

• Compatibility: Tested and confirmed working with WordPress 6.9
• Performance: Added settings caching to reduce database queries
• Performance: Added minified JavaScript for production environments
• Performance: Removed jQuery dependency. It now uses vanilla JavaScript.
• Feature: Added live date preview on settings page
• Feature: Added 6 new calendar systems (Dangi, Ethiopic Amete Alem, Islamic variants)
• Feature: Skip conversion for human-diff format elements
• Fix: Prevent repeated date conversions (elements now processed only once)
• Fix: Always use WordPress site language instead of browser language
• Code Quality: Refactored regex patterns as class constants
• Security: Added direct access prevention checks to all PHP files

1.0.2

• Security: Fixed authenticated (Contributor+) stored XSS vulnerability via date parameter (CVE-2025-8293)
• Security: Added comprehensive input sanitization for all date inputs
• Security: Added proper output escaping for all HTML attributes and content
• Security: Implemented validation for shortcode parameters
• Improvement: Enhanced date validation to prevent malformed input

1.0.1

• Renamed main plugin file to match WordPress.org naming convention (intl-datetime-calendar.php)

1.0.0

• Initial release
• Support for 12 different calendar systems
• WordPress block editor integration
• Automatic locale detection
• WordPress date/time format integration
• SEO-friendly implementation
• Thai Buddhist calendar special handling