wp-includes/class-wp-locale.php:300Retrieves the translated weekday abbreviation.
$weekday_namestringstring public function get_weekday_abbrev( $weekday_name ) { return $this->weekday_abbrev[ $weekday_name ]; }Introduced in 2.1.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-locale.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.