Date Calculator

Add or subtract years, months, weeks, and days from a date. You can also calculate the number of days between two dates with this free date calculator.

Calculate Date

Date result = start date plus or minus years, months, weeks, and days. Days between = end date minus start date.
Your result will appear here.

How the date calculator works

Add to date:
Choose add to date, enter a start date, then enter the years, months, weeks, and days to add.

Subtract from date:
Choose subtract from date to find a date before your starting date.

Days between dates:
Choose days between dates, then enter a start date and end date.

Calendar result:
The calculator uses calendar date math for years and months, then adds or subtracts weeks and days.

Why use a date calculator?

A date calculator is useful for deadlines, appointments, schedules, project timelines, billing periods, events, due dates, travel planning, and counting the number of days between two dates.

It helps avoid mistakes when month lengths, leap years, or longer date ranges are involved.

What your result means

Your result shows either the calculated calendar date after adding or subtracting time, or the number of days between two dates. The result also includes the weekday for easier planning.

Date calculator tips

Frequently asked questions

What is a date calculator?

A date calculator adds or subtracts time from a starting date or calculates the number of days between two dates.

Can this calculator add months?

Yes. You can add or subtract years, months, weeks, and days from a selected date.

Can this calculator count days between dates?

Yes. Select days between dates, enter the start date and end date, and the calculator will show the total days between them.

Does the calculator include the end date?

You can choose whether to include or exclude the end date when calculating days between dates.