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

<?php

//  Date Value, Result

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