Twenty Twenty: Make use of wp_date instead of date_i18n

[sachyya sachet]

As per the new update, it is not recommended to localize time based on WP timestamp: date_i18n( DATE_RFC3339, $timestamp + $offset )

Rather use new wp_date based on Unix timestamp on Twentytwnety theme footer.php L23

[joyously]

Since wp_date is a new function, it has to be used in a way that is backward compatible. Twenty Twenty is labeled as working with WP 4.7.

[sabernhardt]

check if wp_date() function exists before using it in the theme, or else use date_i18n()

[sabernhardt]

I added 48589.diff​ in case that might improve the footer code with more recent WordPress versions.

[poena]

Test Report

This report validates that the indicated patch works without issues.

Patch tested: https://core.trac.wordpress.org/raw-attachment/ticket/48589/48589.diff

Environment

• OS: macOS 14.2.1
• Web Server: Nginx
• PHP: 5.6.39, 8.0.22
• WordPress: 4.7.26 and 6.4.2.
• Browser: Chrome
• Theme: Twenty Twenty

Actual Results

• ✅ No issues found, the date displays correctly.

[audrasjb]

Self assigning for commit consideration.

[audrasjb]

In 57301:

Twenty Twenty: Replace wp_date() with date_i18n().

Since WordPress 5.3 it is recommended to use wp_date() instead of date_i18n(). This changeset replaces the function in Twenty Twenty, with a fallback to date_i18n() for old versions of WordPress.

For more info, see ​https://make.wordpress.org/core/2019/09/23/date-time-improvements-wp-5-3/.

Props sachyya-sachet, joyously, sabernhardt, poena.
Fixes #48589.