PhpSpreadsheet/tests/data/Calculation/DateTime/DAY.php

<?php

//  Date Value, Result

return [
    [
        19,
        22269,
    ],
    [
        1,
        30348,
    ],
    [
        10,
        30843,
    ],
    [
        11,
        '11-Nov-1918',
    ],
    [
        28,
        '28-Feb-1904',
    ],
    [
        '#VALUE!',
        'Invalid',
    ],
    [
        '#NUM!',
        -1,
    ],
];