🔧

Date Add/Subtract

Time & Date · Free Online Tool

Add or subtract years/months/days/hours/minutes/seconds from a date.

By EZ4Code TeamLast updated: 2026-10-29

Base Date

years

months

days

hours

minutes

seconds

Calendar-aware

Uses native Date methods that respect month lengths and leap years.

Six Units

Mix years, months, days, hours, minutes and seconds in one operation.

Add & Subtract

Flip between adding and subtracting with a single click.

How to Use Date Add/Subtract

1Enter the time, date, or value you want to convert.
2Select the target format or timezone.
3The tool calculates the result instantly.
4Copy the converted value for your use.

Features

✓100% free — no signup, no subscription, no ads
✓Runs entirely in your browser — data never leaves your device
✓Fast and lightweight — instant results
✓Cross-platform — works on desktop, tablet, and mobile

Frequently Asked Questions

What timezone is used by default?

The Timestamp Converter uses UTC by default but can display results in your local timezone.

Can I convert timestamps from different programming languages?

Yes, the tool supports Unix timestamps (seconds and milliseconds), ISO 8601, and various date string formats.

Does daylight saving time affect the result?

Timezone conversions apply the daylight saving rules of the selected region. If you need a fixed offset, pick a UTC offset zone instead of a named city.

What is the difference between Unix seconds and milliseconds?

Seconds-based Unix time has 10 digits (typical for servers and databases); milliseconds has 13 digits (typical for JavaScript Date). The converter auto-detects the unit and lets you override it.