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Day-Number

Your daily calendar companion

Day Number & Week Number Today

It's Sunday, November 16, 2025 — day 320 of 365. That leaves 45 days to plan, track, and finish what matters this year.

Use the quick links below for detailed calendars and calculators. See 2025 day numbersReview 2025 week numbersOpen the date calculators

Today's date is Sunday, November 16, 2025

Explore 2025 Day Numbers

View the complete 2025 calendar with day numbers for every date. Track your yearly progress at a glance.

2025 Day Numbers Calendar - Blue Purple Theme

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Explore 2025 Week Numbers

Browse all ISO 8601 week numbers for 2025. Perfect for planning and scheduling across the year.

2025 Week Numbers Calendar - Blue Purple Theme

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Date Calculator Tools

Powerful date calculation tools for counting days, planning events, and tracking deadlines.

🔢

Day Number Calculator

Convert date to day number or find date from day number. Perfect for tracking project milestones or planning seasonal work.

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Week Number Calculator

Convert dates to week numbers or find all dates in a specific week. Perfect for project planning and team coordination.

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Days Between Dates Calculator

Calculate the exact number of days between any two dates. Perfect for planning projects, tracking deadlines, or counting down to special events.

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📆

Days From Today Calculator

Calculate what date it will be in any number of days from today. Perfect for planning events, setting deadlines, or counting forward from a specific date.

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Track day numbers and see where you are in the year

Ever wondered 'What day of the year is today?' Day-Number shows you the day number — along with week numbers, holidays, and timezone support. Perfect for tracking project timelines or just staying organized.

Always current

See today's day number the moment you visit. Teams across time zones use day numbers to keep projects on track.

Leap years? Handled.

We take care of leap years, daylight saving, and time zones automatically — so you don't have to think about it.

Export-ready

Download calendars or export tables directly to your spreadsheets — no formulas needed.

What's a day number?

A day number is the count from January 1st. So Jan 1 = Day Number 1, Dec 31 = Day Number 365 (366 in leap years). Simple.

  • •Track project milestones using day numbers — no manual counting needed.
  • •Compare progress across years with the same day number, even in leap years.
  • •Tell your team 'We're on Day 210' instead of a date — simpler and everyone gets it.
Browse 2025 day numbers

ISO week numbers in practice

ISO-8601 starts weeks on Monday. Week 1 is the week with January 4th. Pair this with day counts for complete time tracking — even in 53-week years.

  • •Keep sprint cadences synchronised across offices by referencing the same ISO week ID.
  • •Plan payroll runs and compliance filings with clear start and end dates for each week.
  • •Spot 53-week years early so you can adjust staffing or reporting windows.
Review 2025 week numbers

How the site keeps results accurate

  1. 1

    Timezone detection

    We start with a default US Eastern timezone on the server, then swap to the visitor's real timezone the moment the page hydrates.

  2. 2

    Standards-based math

    Day numbers and ISO weeks are computed with vetted date-fns utilities and validated against leap-year edge cases.

  3. 3

    Live holiday context

    Upcoming public holidays refresh via our API wrapper so regional work weeks and bridges stay visible.

  4. 4

    Downloadable artefacts

    High-resolution calendar images and tables can be exported or embedded directly into documentation.

Where teams use day number

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Product & engineering

Plan sprints using day numbers. When your team is spread across cities (or continents), day numbers keep everyone on the same page.

Open the week tables
📈

Finance & operations

Use day numbers for payroll cycles and fiscal deadlines. Works even in those weird 53-week years.

Download calendars
🗓️

Event planners

Count forward from today to lock venue holds, invitation sends, and reminder sequences with the Days From Today tool.

Try the forward calculator
🌍

Policy & legal teams

Calculate statutory response periods or contract windows with the Days Between Dates calculator and export the record.

Measure days between dates

Frequently Asked Questions

Q1What's a day number?
A day number is how many days have passed since January 1st. February 1 = Day Number 32. You could count manually, but we calculate the day number for you — leap years and all.
Q2Why use day numbers instead of regular dates?
Day numbers make it easier to track progress. Saying 'Day 200' tells you instantly you're 55% through the year. A regular date like 'July 19' doesn't give you that context. Day numbers simplify project planning.
Q3How often does it update?
Every time you load the page. Once your browser detects your timezone, everything adjusts instantly.
Q4Why does the ISO week sometimes belong to the next year?
ISO-8601 defines Week 1 as the week containing 4 January. When the final days of December fall into that same week, the ISO label switches to the following year. We display the correct tag on the calendar and the tables.
Q5Can I share the results with my team?
Yes. Copy the URL with your language selection, download the annotated calendar image, or export the tables directly to CSV for Slack and documentation threads.
Q6Does the tool account for leap years and daylight saving?
Leap years add a 366th day automatically, and the timezone-aware calculations reflect daylight saving transitions so the day number never drifts.
Q7How should I cite the data in reports?
Reference day-number.com with the specific day or week label, for example "Week 12, 2026 (ISO)". Each view displays the context you need for audit trails.