Date Difference Calculator

Calculate the difference between two dates

This date difference calculator compares two calendar dates and returns both a readable calendar span and fixed-unit totals. It puts dates in chronological order automatically, so entering the later date first produces the same absolute difference.

Calendar units and elapsed units

Years and months are calendar units. Their lengths vary because months contain different numbers of days and leap years add February 29. Total days is the whole calendar-day span; weeks, hours, and minutes are derived from that total.

Output	Meaning
Years, months, days	Calendar breakdown
Total days	Whole days between dates
Total weeks	Complete seven-day groups
Total hours	Total days × 24
Total minutes	Total days × 1,440

Only the date portion is used. Time of day, time zones, and daylight-saving clock changes do not affect the result.

Common uses

• project milestones and delivery dates
• contract, subscription, and billing periods
• event and travel planning
• anniversary and historical date checks
• countdown planning in whole days

Date difference versus age calculation

Use date difference for any two dates and a general duration. Use an age calculator when the starting date is a birth date and you need age-specific details such as the next birthday.

Tool	Best for	Typical result
Date difference	Any two calendar dates	Calendar span and total units
Age calculator	Birth date to target date	Age and next birthday
Countdown timer	A live future event	Remaining time that updates

Code examples

JavaScript

const start = new Date(2024, 0, 15);
const end = new Date(2024, 1, 20);
const totalDays = Math.floor(
  (Date.UTC(end.getFullYear(), end.getMonth(), end.getDate()) -
    Date.UTC(start.getFullYear(), start.getMonth(), start.getDate())) /
    86400000,
);

Python

from datetime import date

start = date(2024, 1, 15)
end = date(2024, 2, 20)
total_days = (end - start).days

SQL

SELECT DATE '2024-02-20' - DATE '2024-01-15' AS total_days;