# Add subtract days

> Add or subtract years, months and days.

[Open tool](https://www.toolcabana.com/lb/date-calculator) · [Dates and productivity](https://www.toolcabana.com/lb/category/dates-and-productivity)

Tool ID: date-calculator. Requested language: lb. Description language: en. Complete guide translation: no; untranslated sections use English.

## Overview (en)

Add subtract days takes a starting date and adds or subtracts a number of years, months and days, returning the resulting date in YYYY-MM-DD form. Years are applied first, then months, then days. Negative values subtract, and when a month-end day does not exist, such as February 30, the date is moved to the last valid day.

## Supported tasks (en)

Add or subtract years, months and days.

## Steps (en)

1. Adjust the values; an initial result is calculated from the defaults.
2. Change the basic settings or open Advanced mode to fine-tune the result.
3. Review and copy or download your result. Pause Live results to run manually. Sources or individual settings above 20,000 characters require an explicit run.

## Settings

- Starting date (en; key: start; type: date)
- Years to add (en; key: years; type: number)
- Months to add (en; key: months; type: number)
- Days to add (en; key: days; type: number)

## Limitations (en)

Use finite numbers, valid dates and the ranges shown by each control. Invalid values produce an error without a downloadable result.

## Privacy and connections (en)

This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.

## Questions (en)

### What date is 90 days from today?

Leave the starting date as today, set Days to add to 90 and keep years and months at 0. The result is the calendar date exactly 90 days later, counted through month lengths and leap years.

### How do I subtract months from a date?

Enter a negative number in Months to add, such as -6. Negative values work for years, months and days. Ranges are -1000 to 1000 years, -12000 to 12000 months and -365000 to 365000 days.

### What happens when I add one month to January 31?

February has no 31st, so the calculator moves the result to the last valid day: February 28, or February 29 in a leap year. Years are added before months, and months before days, which matters when combining all three.

### Where is my input processed?

This operation processes its source in your browser. Copy and download are explicit actions; source input is not saved in an account or history.

### What are the input limits?

Use finite numbers, valid dates and the ranges shown by each control. Invalid values produce an error without a downloadable result.

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