Add or subtract days

Find a date by adding or subtracting a whole number of days.

Your dates and times stay in your browser and are not stored.

Method and assumptions

Method version 1.0.0 · Updated September 22, 2026

Shift a date

Formula: Start date + number of days

Gregorian civil dates from years 0001 to 9999, without time or timezone. A negative number subtracts days; zero keeps the date. Every day counts, including weekends and holidays. Example: March 1, 2024 − 1 day = February 29, 2024.

date: Start date
days: Number of days (signed)

Gregorian calendar from years 0001 to 9999. Date, duration and rounding conventions are specified for each mode.

Calculate with code

These short examples use the same inputs and core calculation as this tool. Adapt validation and formatting to your application.

JavaScript

const shifted = new Date(Date.UTC(2026, 0, 1) + 10 * 86_400_000);
console.log(shifted.toISOString().slice(0, 10)); // 2026-01-11

TypeScript

const shifted = new Date(Date.UTC(2026, 0, 1) + 10 * 86_400_000);
console.log(shifted.toISOString().slice(0, 10)); // 2026-01-11

Python

from datetime import date, timedelta
print(date(2026, 1, 1) + timedelta(days=10))  # 2026-01-11

Java

var start = java.time.LocalDate.of(2026, 1, 1);
System.out.println(start.plusDays(10)); // 2026-01-11

var start = new DateOnly(2026, 1, 1);
Console.WriteLine(start.AddDays(10)); // 01/11/2026 (format depends on culture)