Per validare le date in lato frontend attraverso javascript:

var dateRegex = /^(?=\d)(?:(?:31(?!.(?:0?[2469]|11))|(?:30|29)(?!.0?2)|29(?=.0?2.(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(?:\x20|$))|(?:2[0-8]|1\d|0?[1-9]))([-.\/])(?:1[012]|0?[1-9])\1(?:1[6-9]|[2-9]\d)?\d\d(?:(?=\x20\d)\x20|$))?(((0?[1-9]|1[012])(:[0-5]\d){0,2}(\x20[AP]M))|([01]\d|2[0-3])(:[0-5]\d){1,2})?$/;
console.log( dateRegex.test( $('your input').val() ) );

Oppure:

validate_ddmmyyyy(value){
    var dateRegex = /^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/;
    if(dateRegex.test(value)){
        

    }
}

ESTRAPOLAZIONE GRAFICA

• https://regexper.com/