Comparing two dates

JavaScript:
Comparing two dates

How to:

JavaScript’s Date objects come in handy. When you compare them, they convert into milliseconds since January 1, 1970, UTC.

let date1 = new Date('2021-07-24');
let date2 = new Date('2021-07-25');

console.log(date1 < date2); // true
console.log(date1 > date2); // false
console.log(date1.getTime() === date2.getTime()); // false

Sample output:

true
false
false

Deep Dive

Under the hood, Date objects are just milliseconds. Historically, programmers had to manage date operations manually, calculating the time elapsed from a datum-point, often risking errors. Comparing Date objects makes life easier, though yet not error-proof, especially with time zones and daylight saving time.

Alternatives? Sure. Libraries like moment.js or date-fns help handle complex scenarios and provide additional conveniences for date manipulation.

Implementation wise, it’s key to remember that directly comparing Date objects (with ==) compares references, not values. Use getTime() for an accurate value comparison. And watch out for time zones when parsing dates; it’s easy to get tripped up if you’re not careful.

JavaScript:Comparing two dates

How to:

Deep Dive

See Also

JavaScript:
Comparing two dates