How to Compare Two Dates in JavaScript: Simple Guide

To compare two dates in JavaScript, convert them to Date objects and use comparison operators like <, >, or ===. You can also compare their time values using getTime() for precise equality or ordering.

Syntax

To compare two dates, first create Date objects. Then use comparison operators or the getTime() method to compare their numeric time values.

• date1 < date2: checks if date1 is before date2.
• date1 > date2: checks if date1 is after date2.
• date1.getTime() === date2.getTime(): checks if both dates are exactly the same moment.

javascript

const date1 = new Date('2024-06-01');
const date2 = new Date('2024-06-02');

// Compare using operators
console.log(date1 < date2);  // true
console.log(date1 > date2);  // false

// Compare exact equality
console.log(date1.getTime() === date2.getTime());  // false

Output

true
false
false

Example

This example shows how to compare two dates to find which one is earlier, later, or if they are the same.

javascript

const dateA = new Date('2024-06-10T10:00:00');
const dateB = new Date('2024-06-10T15:00:00');

if (dateA.getTime() === dateB.getTime()) {
  console.log('Dates are the same');
} else if (dateA < dateB) {
  console.log('dateA is before dateB');
} else {
  console.log('dateA is after dateB');
}

Output

dateA is before dateB

Common Pitfalls

Many beginners try to compare dates directly as strings or objects, which does not work as expected because Date objects are not primitive values.

Also, using == or === on Date objects compares references, not the actual date values.

javascript

const d1 = new Date('2024-06-01');
const d2 = new Date('2024-06-01');

// Wrong: compares object references
console.log(d1 === d2);  // false

// Right: compare time values
console.log(d1.getTime() === d2.getTime());  // true

Output

false
true

Quick Reference

Operation	Description	Example
Check if date1 is before date2	Use < operator	date1 < date2
Check if date1 is after date2	Use > operator	date1 > date2
Check if dates are exactly equal	Compare getTime() values	date1.getTime() === date2.getTime()
Create a Date object	Use new Date()	const d = new Date('2024-06-01')

Key Takeaways

Always convert strings or other formats to Date objects before comparing.

Use comparison operators (<, >) to check order between dates.

Use getTime() to compare exact equality of two dates.

Never compare Date objects directly with === or == as it compares references.

Remember Date objects represent moments in time including hours, minutes, and seconds.