How to validate a date?

Question

I\'m trying to test to make sure a date is valid in the sense that if someone enters 2/30/2011 then it should be wrong.

How can I do this with any date?

Answer 1

Though this was raised long ago, still a most wanted validation. I found an interesting blog with few function.

/* Please use these function to check the reuslt only. do not check for otherewise. other than utiljs_isInvalidDate

Ex:-

utiljs_isFutureDate() retuns only true for future dates. false does not mean it is not future date. it may be an invalid date.

practice :

call utiljs_isInvalidDate first and then use the returned date for utiljs_isFutureDate()

var d = {};

if(!utiljs_isInvalidDate('32/02/2012', d))

if(utiljs_isFutureDate(d))

//date is a future date

else

// date is not a future date



 */

function utiljs_isInvalidDate(dateStr, returnDate) {

    /*dateStr | format should be dd/mm/yyyy, Ex:- 31/10/2017

     *returnDate will be in {date:js date object}.

     *Ex:- if you only need to check whether the date is invalid,

     * utiljs_isInvalidDate('03/03/2017')

     *Ex:- if need the date, if the date is valid,

     * var dt = {};

     * if(!utiljs_isInvalidDate('03/03/2017', dt)){

     *  //you can use dt.date

     * }

     */

    if (!dateStr)
        return true;
    if (!dateStr.substring || !dateStr.length || dateStr.length != 10)
        return true;
    var day = parseInt(dateStr.substring(0, 2), 10);
    var month = parseInt(dateStr.substring(3, 5), 10);
    var year = parseInt(dateStr.substring(6), 10);
    var fullString = dateStr.substring(0, 2) + dateStr.substring(3, 5) + dateStr.substring(6);
    if (null == fullString.match(/^\d+$/)) //to check for whether there are only numbers
        return true;
    var dt = new Date(month + "/" + day + "/" + year);
    if (dt == 'Invalid Date' || isNaN(dt)) { //if the date string is not valid, new Date will create this string instead
        return true;
    }
    if (dt.getFullYear() != year || dt.getMonth() + 1 != month || dt.getDate() != day) //to avoid 31/02/2018 like dates
        return true;
    if (returnDate)
        returnDate.date = dt;
    return false;
}

function utiljs_isFutureDate(dateStrOrObject, returnDate) {
    return utiljs_isFuturePast(dateStrOrObject, returnDate, true);
}

function utiljs_isPastDate(dateStrOrObject, returnDate) {
    return utiljs_isFuturePast(dateStrOrObject, returnDate, false);
}

function utiljs_isValidDateObjectOrDateString(dateStrOrObject, returnDate) { //this is an internal function
    var dt = {};
    if (!dateStrOrObject)
        return false;
    if (typeof dateStrOrObject.getMonth === 'function')
        dt.date = new Date(dateStrOrObject); //to avoid modifying original date
    else if (utiljs_isInvalidDate(dateStrOrObject, dt))
        return false;
    if (returnDate)
        returnDate.date = dt.date;
    return true;

}

function utiljs_isFuturePast(dateStrOrObject, returnDate, isFuture) { //this is an internal function, please use isFutureDate or isPastDate function
    if (!dateStrOrObject)
        return false;
    var dt = {};
    if (!utiljs_isValidDateObjectOrDateString(dateStrOrObject, dt))
        return false;
    today = new Date();
    today.setHours(0, 0, 0, 0);
    if (dt.date)
        dt.date.setHours(0, 0, 0, 0);
    if (returnDate)
        returnDate.date = dt.date;
    //creating new date using only current d/m/y. as td.date is created with string. otherwise same day selection will not be validated.
    if (isFuture && dt.date && dt.date.getTime && dt.date.getTime() > today.getTime()) {
        return true;
    }
    if (!isFuture && dt.date && dt.date.getTime && dt.date.getTime() < today.getTime()) {
        return true;
    }
    return false;
}

function utiljs_isLeapYear(dateStrOrObject, returnDate) {
    var dt = {};
    if (!dateStrOrObject)
        return false;
    if (utiljs_isValidDateObjectOrDateString(dateStrOrObject, dt)) {
        if (returnDate)
            returnDate.date = dt.date;
        return dt.date.getFullYear() % 4 == 0;
    }
    return false;
}

function utiljs_firstDateLaterThanSecond(firstDate, secondDate, returnFirstDate, returnSecondDate) {
    if (!firstDate || !secondDate)
        return false;
    var dt1 = {},
    dt2 = {};
    if (!utiljs_isValidDateObjectOrDateString(firstDate, dt1) || !utiljs_isValidDateObjectOrDateString(secondDate, dt2))
        return false;
    if (returnFirstDate)
        returnFirstDate.date = dt1.date;
    if (returnSecondDate)
        returnSecondDate.date = dt2.date;
    dt1.date.setHours(0, 0, 0, 0);
    dt2.date.setHours(0, 0, 0, 0);
    if (dt1.date.getTime && dt2.date.getTime && dt1.date.getTime() > dt2.date.getTime())
        return true;
    return false;
}

function utiljs_isEqual(firstDate, secondDate, returnFirstDate, returnSecondDate) {
    if (!firstDate || !secondDate)
        return false;
    var dt1 = {},
    dt2 = {};
    if (!utiljs_isValidDateObjectOrDateString(firstDate, dt1) || !utiljs_isValidDateObjectOrDateString(secondDate, dt2))
        return false;
    if (returnFirstDate)
        returnFirstDate.date = dt1.date;
    if (returnSecondDate)
        returnSecondDate.date = dt2.date;
    dt1.date.setHours(0, 0, 0, 0);
    dt2.date.setHours(0, 0, 0, 0);
    if (dt1.date.getTime && dt2.date.getTime && dt1.date.getTime() == dt2.date.getTime())
        return true;
    return false;
}

function utiljs_firstDateEarlierThanSecond(firstDate, secondDate, returnFirstDate, returnSecondDate) {
    if (!firstDate || !secondDate)
        return false;
    var dt1 = {},
    dt2 = {};
    if (!utiljs_isValidDateObjectOrDateString(firstDate, dt1) || !utiljs_isValidDateObjectOrDateString(secondDate, dt2))
        return false;
    if (returnFirstDate)
        returnFirstDate.date = dt1.date;
    if (returnSecondDate)
        returnSecondDate.date = dt2.date;
    dt1.date.setHours(0, 0, 0, 0);
    dt2.date.setHours(0, 0, 0, 0);
    if (dt1.date.getTime && dt2.date.getTime && dt1.date.getTime() < dt2.date.getTime())
        return true;
    return false;
}

copy the whole code into a file and include.

hope this helps.