[brandonkelly]

Description

Generated field templates printed dates however PHP stringified them, so cards showed raw values:

Template	Before	After (en-US site)
{startDate} (Date field, loaded from the DB)	2026-10-09 10:00:00	10/9/2026, 10:00 AM PDT
{startDate} (Date field set from code as a DateTime)	save throws Object of class DateTime could not be converted to string	10/9/2026, 10:00 AM PDT
{postDate}	2026-03-04T13:06:00+00:00	3/4/2026, 5:06 AM
{startDate|date('Y')}	2026	2026

Generated field values are stored when an element is saved and differ by site, so they’re now formatted in the element’s site language, the same way entry title formats are rendered.

 ElementWrites::completeGeneratedFields()
   foreach site element
     foreach generated field
-      renderObjectTemplate(template, element)
+      I18N::withLocale(site language)
+        renderObjectTemplate(template, element, generatedFieldDateVariables(element, template))

generatedFieldDateVariables() passes each date attribute or custom field that the template references as a Carbon copy whose string form matches the date’s card preview:

• custom fields use their own getPreviewHtml(), so date-only fields print only the date and time zones show the way they do in cards
• native date attributes such as postDate use the formatter’s short date and time

Object template variables take precedence over the element’s own values for {foo} shorthand. Filters such as |date still receive a date. Full Twig like {{ object.startDate }} still prints the element’s own value.

Stored values change the next time their elements are saved. Run php artisan craft:resave:all to update existing values.

Evidence

• Before: SaveElementTest › “formats dates that generated fields print in the site’s locale” fails on 6.x: Object of class DateTime could not be converted to string.
  After: It passes. A de site with the template {startDate} | {day} | {postDate} | {startDate|date("Y")} | [{endDate}] stores 09.10.2026, 10:00 PDT | 28.02.2027 | 04.03.2026, 05:06 | 2026 | [].
• composer ci: Pint, Rector, PHPStan, and the core suite pass (12,425 tests). tests-adapter has 3 failures (Legacy\ConfigCompatibilityTest, Legacy\Markdown\LegacyMarkdownTest) that also fail on unchanged 6.x and pass when run alone.

[github-actions]

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