Calendar & Date Tools

A free set of date tools that run entirely in your browser — calculate the days between two dates, add or subtract days, count down to any date, find the week number, and check leap years. No sign-up, nothing uploaded.

Yearly Calendar

The whole year on one printable page — all 12 months, weekends in red, with selectable weekend days. Updates to the new year automatically.

Date Calculator

Days between two dates, or add and subtract days, weeks, months and years from any date. Includes weekday and business-day counts.

Days Until Any Date

A live countdown to any date you choose — plus ready-made counters for Christmas, New Year, Halloween, Thanksgiving and summer.

How Many Days in a Year

365 or 366? A clear answer with the leap-year rule, the number of weeks and months, and this year's exact count.

Week Number

What week is it? See the current ISO-8601 week number, or look up the week number, week of year and day of year for any date.

Leap Year Checker

Is a given year a leap year? Instant answer with the divisible-by-4 rule and a table of upcoming leap years.

Days Until Christmas

A live countdown to December 25 — days, hours, minutes and seconds until Christmas this year.
100% free, no sign-up Runs in your browser — nothing uploaded Instant, works offline

One place for everyday date math

Whether you're counting down to a deadline, working out an anniversary, or checking which week of the year it is, these tools give you an exact answer in a click.

Dates are deceptively tricky: months have different lengths, leap years add a day every four years (with exceptions), and "how many weeks until…" depends on where you start counting. Each tool here handles those edge cases correctly using calendar-accurate math, so you don't have to count on your fingers or wrestle with a spreadsheet formula.

Everything is calculated locally in your browser. That means results are instant, your dates never leave your device, and the tools keep working even without a connection. Pick a tool above to get started, or jump straight to the date calculator — the most versatile of the set.

Frequently Asked Questions

Are these calendar tools free?
Yes — every tool is completely free with no sign-up and no limits. All the date math runs in your browser, so nothing you type is uploaded to a server.
Do the tools work offline?
Once a page has loaded, calculations run entirely on your device with plain JavaScript, so they keep working even if your connection drops. There is no server round-trip for any result.
Which tool counts the days between two dates?
Use the Date Calculator. Its difference mode gives the exact number of days between two dates, plus the breakdown in years, months and days, the number of weeks, and the number of weekdays in the span.
Can I count down to a holiday or a personal date?
Yes. The Days Until tool counts down to any date you pick, and there are dedicated live countdowns for Christmas, New Year, Halloween, Thanksgiving and the first day of summer.