PhpSpreadsheet/tests/rawTestData/Shared/Date/FormatCodes.php

<?php

//  Excel Format Code                     Result
return [
    [ 'General',                          FALSE ],
    [ '@',                                FALSE ],
    [ '0',                                FALSE ],
    [ '0.00',                             FALSE ],
    [ '#,##0.00',                         FALSE ],
    [ '#,##0.00_-',                       FALSE ],
    [ '0%',                               FALSE ],
    [ '0.00%',                            FALSE ],
    [ 'yyyy-mm-dd',                       TRUE  ],
    [ 'yy-mm-dd',                         TRUE  ],
    [ 'dd/mm/yy',                         TRUE  ],
    [ 'd/m/y',                            TRUE  ],
    [ 'd-m-y',                            TRUE  ],
    [ 'd-m',                              TRUE  ],
    [ 'm-y',                              TRUE  ],
    [ 'mm-dd-yy',                         TRUE  ],
    [ 'd-mmm-yy',                         TRUE  ],
    [ 'd-mmm',                            TRUE  ],
    [ 'mmm-yy',                           TRUE  ],
    [ 'm/d/yy h:mm',                      TRUE  ],
    [ 'd/m/y h:mm',                       TRUE  ],
    [ 'h:mm AM/PM',                       TRUE  ],
    [ 'h:mm:ss AM/PM',                    TRUE  ],
    [ 'h:mm',                             TRUE  ],
    [ 'h:mm:ss',                          TRUE  ],
    [ 'mm:ss',                            TRUE  ],
    [ 'h:mm:ss',                          TRUE  ],
    [ 'i:s.S',                            TRUE  ],
    [ 'h:mm:ss;@',                        TRUE  ],
    [ 'yy/mm/dd;@',                       TRUE  ],
    [ '"$" #,##0.00_-',                   FALSE ],
    [ '$#,##0_-',                         FALSE ],
    [ '[$EUR ]#,##0.00_-',                FALSE ],
    [ '_[$EUR ]#,##0.00_-',               FALSE ],
    [ '[Green]#,##0.00;[Red]#,##0.00_-',  FALSE ],
    [ '#,##0.00 "dollars"',               FALSE ],
];