app/Date/AbstractCalendarDate.php
protected function dayNamesAbbreviated(int $day_number): string
    {
        static $translated_day_names;

        if ($translated_day_names === null) {
            $translated_day_names = [
                /* I18N: abbreviation for Monday */
                0 => I18N::translate('Mon'),
                /* I18N: abbreviation for Tuesday */
                1 => I18N::translate('Tue'),
                /* I18N: abbreviation for Wednesday */
                2 => I18N::translate('Wed'),
                /* I18N: abbreviation for Thursday */
                3 => I18N::translate('Thu'),
                /* I18N: abbreviation for Friday */
                4 => I18N::translate('Fri'),
                /* I18N: abbreviation for Saturday */
                5 => I18N::translate('Sat'),
                /* I18N: abbreviation for Sunday */
                6 => I18N::translate('Sun'),
            ];
        }

        return $translated_day_names[$day_number];
    }
protected function dayNamesAbbreviated(int $day_number): string
    {
        static $translated_day_names;

        if ($translated_day_names === null) {
            $translated_day_names = [
                /* I18N: abbreviation for Monday */
                0 => I18N::translate('Mon'),
                /* I18N: abbreviation for Tuesday */
                1 => I18N::translate('Tue'),
                /* I18N: abbreviation for Wednesday */
                2 => I18N::translate('Wed'),
                /* I18N: abbreviation for Thursday */
                3 => I18N::translate('Thu'),
                /* I18N: abbreviation for Friday */
                4 => I18N::translate('Fri'),
                /* I18N: abbreviation for Saturday */
                5 => I18N::translate('Sat'),
                /* I18N: abbreviation for Sunday */
                6 => I18N::translate('Sun'),
            ];
        }

        return $translated_day_names[$day_number];
    }
protected function dayNamesAbbreviated ( int $ day_number ) : string { static $ translated_day_names ; if ( $ translated_day_names === null ) { $ translated_day_names = [ /* I18N: abbreviation for Monday */ 0 => I18N :: translate ( 'Mon' ) , /* I18N: abbreviation for Tuesday */ 1 => I18N :: translate ( 'Tue' ) , /* I18N: abbreviation for Wednesday */ 2 => I18N :: translate ( 'Wed' ) , /* I18N: abbreviation for Thursday */ 3 => I18N :: translate ( 'Thu' ) , /* I18N: abbreviation for Friday */ 4 => I18N :: translate ( 'Fri' ) , /* I18N: abbreviation for Saturday */ 5 => I18N :: translate ( 'Sat' ) , /* I18N: abbreviation for Sunday */ 6 => I18N :: translate ( 'Sun' ) , ] ; } return $ translated_day_names [ $ day_number ] ; }
Abbreviated day of the week

@param int $day_number

@return string
Abbreviated day of the week