Is the Date Calculator free?

Yes — the Date Calculator is completely free, with no account, subscription, signup, or usage limits.

Is my data uploaded or stored?

No. The Date Calculator processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.

Does the Date Calculator work offline?

Yes. Once the page has finished loading, the Date Calculator works without an internet connection.

Which browsers does the Date Calculator work in?

The Date Calculator works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.

How are business days calculated?

Business days count only Monday through Friday — Saturdays and Sundays are excluded. Public holidays are not automatically excluded (they vary by country), so if your calculation spans a holiday period, subtract the relevant holidays from the result manually.

Does "Add 1 month" always add exactly 30 days?

No — adding one month moves to the same date in the next calendar month, regardless of how many days that month has. For example, 31 January + 1 month = 28 February (or 29 February in a leap year), not 2 March. This is standard date arithmetic and matches how contracts and legal deadlines are typically calculated.

Can I calculate someone's exact age with this tool?

Yes. Use Date Difference mode: set "From Date" to the person's date of birth and "To Date" to today. The Breakdown result will show their exact age in years, months, and days.

Date Calculator

Add or subtract days, weeks, months, and years from any date to find a future or past date.

Start Date

Operation

Amount

Unit

Result

Thursday, August 6, 2026

+30 days from July 7, 2026

Free browser-based tool · Runs 100% on your device · Last updated July 7, 2026

What is the Date Calculator?

The free Date Calculator has two modes: Add / Subtract Date lets you add or subtract days, weeks, months, or years from any date to find a future or past date; Date Difference calculates the gap between two dates in total days, weeks, months, and business days — with a precise breakdown of years, months, and remaining days. No formulas or manual counting needed.

→ Find a deadline 30 or 90 days from a contract signing date
→ Calculate how many days until (or since) an important date or anniversary
→ Work out the exact number of business days between two project milestones
→ Find someone's exact age in years, months, and days
→ Calculate invoice due dates, subscription renewal dates, or notice periods

How to Use the Date Calculator

1 Select a mode using the toggle at the top: Add / Subtract Date or Date Difference.
2 Add / Subtract mode: enter a Start Date, choose Add or Subtract, enter a number, and select Days / Weeks / Months / Years. The result date appears instantly.
3 Date Difference mode: enter a From Date and a To Date. The tool shows the gap in total days, weeks, approximate months, and business days.
4 In Date Difference mode, the Breakdown section shows the exact split in years, months, and remaining days for a precise result.

Key Features

📅
Two calculation modes

Add/subtract durations from a date, or find the difference between two dates.
💼
Business days

Date Difference mode counts weekday-only (Mon–Fri) business days between two dates.
🔍
Precise breakdown

Shows the exact difference as years + months + days, not just total days.
🔄
All time units

Works with days, weeks, months, and years in both directions.

Example Usage

Example Input

Mode: Date Difference
From: 15 January 2025
To:   30 June 2025

Example Output

Total Days:     166 days
Weeks:          23.7 weeks
Months:         ~5 months
Business Days:  119 days

Breakdown: 0 years, 5 months, 15 days

Frequently Asked Questions about the Date Calculator

What is the Date Calculator?: The Date Calculator is a free online tool that lets you add or subtract days, weeks, months, and years from any date to find a future or past date. It runs entirely in your browser, so there is nothing to install and nothing is uploaded to a server.
Is the Date Calculator free?: Yes — the Date Calculator is completely free, with no account, subscription, signup, or usage limits.
Is my data uploaded or stored?: No. The Date Calculator processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.
Does the Date Calculator work offline?: Yes. Once the page has finished loading, the Date Calculator works without an internet connection.
Which browsers does the Date Calculator work in?: The Date Calculator works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.
How are business days calculated?: Business days count only Monday through Friday — Saturdays and Sundays are excluded. Public holidays are not automatically excluded (they vary by country), so if your calculation spans a holiday period, subtract the relevant holidays from the result manually.
Does "Add 1 month" always add exactly 30 days?: No — adding one month moves to the same date in the next calendar month, regardless of how many days that month has. For example, 31 January + 1 month = 28 February (or 29 February in a leap year), not 2 March. This is standard date arithmetic and matches how contracts and legal deadlines are typically calculated.
Can I calculate someone's exact age with this tool?: Yes. Use Date Difference mode: set "From Date" to the person's date of birth and "To Date" to today. The Breakdown result will show their exact age in years, months, and days.