Calculate dates &
time differences. Free.

The date calculator lets you find the number of days, weeks, months, or years between two dates; add or subtract days, weeks, months, or years from a given date; find out what day of the week a date falls on; and calculate working days (excluding weekends) between two dates. It handles leap years, month-end edge cases, and historical dates automatically.

Set the start date to today and enter your future date as the end date. The calculator will show exactly how many days, weeks, and months remain. This is useful for counting down to events like birthdays, holidays, project deadlines, contract end dates, or any other important milestone.

Yes. The date calculator fully accounts for leap years (years divisible by 4, except century years not divisible by 400). February has 29 days in a leap year, and this is correctly factored into all calculations involving date differences or date additions. You do not need to adjust for leap years manually.

Working days (also called business days) are days from Monday to Friday, excluding weekends (Saturday and Sunday). The calculator counts only these days when calculating working-day differences between two dates. Note that public holidays are not excluded, as these vary by country and region. If you need to account for specific holidays, subtract them manually from the result.

Yes. Enter the person's birth date as the start date and today as the end date. The calculator will show the exact number of days, weeks, months, and years since that date — giving you a precise age calculation that accounts for all leap years in between.

The date calculator can handle dates within the range supported by JavaScript's Date object, which covers dates from approximately the year 100 CE to the year 9999 CE. For most practical purposes — project planning, personal finance, historical research, and everyday date math — this range is more than sufficient.

Adding a calendar month means advancing to the same day in the next month — for example, January 31 + 1 month = February 28 (or 29 in a leap year). Adding 30 days is always exactly 30 days, regardless of the months involved. These two operations produce different results, especially near month-ends. The calculator uses calendar months when you select "months" as the unit.

The calculator provides mathematically accurate date calculations based on the Gregorian calendar. However, for legal, financial, or contractual purposes, always verify results and consult a professional if needed — some jurisdictions define "days" or "months" differently in legal contexts (for example, excluding the start date or including the end date in a count).