How do I add days to a date?

Enter the start date, select 'Add' operation, enter the number of days, and click Calculate. The calculator will add the specified days to your start date.

Can I add weeks, months, or years?

Yes, you can add or subtract days, weeks, months, or years. Select the appropriate unit from the dropdown menu before calculating.

How accurate is the date calculation?

The calculator uses JavaScript Date object which handles month and year boundaries correctly. For example, adding 1 month to January 31 will result in February 28/29 depending on the year.

What happens when I subtract days?

Select 'Subtract' operation and enter the number of days. The calculator will subtract that many days from your start date, going back in time.

Can I calculate business days only?

This calculator calculates calendar days. For business days (excluding weekends and holidays), you would need a specialized business day calculator.

How do I find a date 30 days from today?

Enter today's date as the start date, select 'Add', enter 30, select 'Days' as the unit, and click Calculate. The result will show the date 30 days from today.

Add/Subtract Days

Find a future or past date by adding or subtracting days, weeks, months, or years.

Calculate Date

Result

Enter values and calculate to see results

Formula & Guide

Date Calculation Methods

+

Add Days

New Date = Start Date + Days

Add specified number of days to start date

-

Subtract Days

New Date = Start Date - Days

Subtract specified number of days from start date

Step-by-Step Scenario

Example Scenario

Start Date

January 15, 2024

Operation

Add 30 days

1

Start with Base Date

Start Date: January 15, 2024

2

Add Days

January 15 + 30 days

Result: February 14, 2024

Additional Examples

Add 1 Month

Start: Jan 31, 2024

Add: 1 month

Result

February 29, 2024 (leap year)

Subtract 2 Weeks

Start: March 15, 2024

Subtract: 2 weeks

Result

March 1, 2024

Characteristics of Date Calculation

Multiple Units

Supports days, weeks, months, and years. Automatically handles month and year boundaries correctly.

Bidirectional

Add or subtract time from any date. Perfect for finding future deadlines or past dates.

Accurate Calculations

Uses JavaScript Date object which correctly handles leap years, month lengths, and year boundaries.

Easy to Use

Simple interface: select date, choose operation, enter amount, and get instant results.

Important Notes

The calculator handles month and year boundaries automatically. Adding 1 month to January 31 will result in February 28/29.
Leap years are automatically accounted for. February 29 exists only in leap years.
When adding months, the day of month is preserved when possible. If the target month has fewer days, the last day of that month is used.
Week calculations are based on 7-day weeks. Adding 1 week = adding 7 days.
For business days (excluding weekends), you would need a specialized calculator that accounts for weekends and holidays.

Frequently Asked Questions

Find answers to common questions about date calculations.