Calendar tools · holidays · how-tos
Free calendar tools and holiday dates that just work.
Quick answers for everyday calendar questions: week numbers, business days, holiday dates, sports and finance schedules, and step-by-step guides for Google Calendar, Outlook, and Apple Calendar.
Most-used tools
All client-side. Inputs never leave your browser.
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Week Number
What ISO week is today? Look up any date.
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Days Between Dates
Calendar days, business days, weeks, months.
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Date Calculator
Add or subtract days, weeks, months, years.
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Age Calculator
Exact age in years, months, days, hours.
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Countdown
Days until Christmas, New Year, and more.
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Week Numbers
Full ISO week tables for 2025–2028.
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Explore the site
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Holidays & Observances
US federal holidays, monthly observances, 50 states, 30 countries.
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Calendar How-To Guides
27 tutorials for Google Calendar, Outlook, and Apple Calendar.
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Sports Schedules
NFL, NBA, MLB, Premier League, Champions League, F1, Real Madrid.
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Financial Calendars
Economic data, FOMC, earnings season, tax deadlines, market holidays.
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Cultural Calendars
Lunar, Islamic, Hebrew, Chinese, Hindu, Buddhist, Persian, more.
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Smart-Calendar Reviews
Skylight, Echo Show, Hearth — hands-on family-display reviews.
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What's on this site?
The Calendar covers six things calendar users actually search for:
- Quick tools — week numbers, date math, age, and countdowns. No sign-up.
- Holiday data — US federal, by state, by country, by month. With observed-day rules.
- How-to guides — plain-English instructions for Google, Outlook, and Apple Calendar.
- Sports schedules — season structures plus official iCal subscription links.
- Finance calendars — FOMC dates, economic releases, earnings, taxes.
- Cultural calendars — Lunar, Islamic, Hebrew, Chinese, Hindu, Buddhist, Persian, Ethiopian, Coptic, Japanese.
Everything is free, factual, and runs in your browser. Tools never send your inputs anywhere — calculations are 100% client-side.