Checking if two Dates have the same date info

Question

How can I check if two different date objects have the same date information(having same day, month, year ...)? I have tried "==", "===" and .equals but

Answer 1

Hellnar,

you could try (pardon the function name :) - amended per felix's valueof, rather than getTime)

function isEqual(startDate, endDate) {
    return endDate.valueOf() == startDate.valueOf();
}

usage:

if(isEqual(date1, date2)){
   // do something
}

might get you part of the way there.

see also:

'http://www.java2s.com/Tutorial/JavaScript/0240__Date/DatevalueOf.htm'

Answer 2

A simple single line alternative for determining if two dates are equal, ignoring the time part:

function isSameDate(a, b) {
    return Math.abs(a - b) < (1000 * 3600 * 24) && a.getDay() === b.getDay();
}

It determines if dates a and b differ no more than one day and share the same day of the week.

function isSameDate(a, b) {
    return Math.abs(a - b) < (1000 * 3600 * 24) && a.getDay() === b.getDay();
}

console.log(isSameDate(new Date(2017, 7, 21), new Date(2017, 7, 21))); //exact same date => true
console.log(isSameDate(new Date(2017, 7, 21, 23, 59, 59), new Date(2017, 7, 21))); //furthest same dates => true
console.log(isSameDate(new Date(2017, 7, 20, 23, 59, 59), new Date(2017, 7, 21))); //nearest different dates => false
console.log(isSameDate(new Date(2016, 7, 21), new Date(2017, 7, 21))); //different year => false
console.log(isSameDate(new Date(2017, 8, 21), new Date(2017, 7, 21))); //different month => false