Time systems, calendar references, and timezone tools.

Calendar section

Yearly Calendars and Calendar Tools

Open a printable calendar for any year from 2025 to 2030, find week numbers, count working days, and look up day-of-year codes. Plan around the calendar’s actual rules, from Monday starts to leap-day exceptions.

Find your calendar tool

Yearly calendars

  • 2025 Calendar

    All 12 months of 2025 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

  • 2026 Calendar

    All 12 months of 2026 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

  • 2027 Calendar

    All 12 months of 2027 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

  • 2028 Calendar

    All 12 months of 2028 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

  • 2029 Calendar

    All 12 months of 2029 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

  • 2030 Calendar

    All 12 months of 2030 with ISO week numbers, US federal holidays, full and new moons, and clock-change dates. Printable.

Plan by week

  • Week Number

    Current ISO week number with yearly context and even-odd scheduling help.

  • ISO vs US Weeks

    See how week numbering changes between the main systems people confuse.

Plan by business day

  • Working Days

    Count business days between dates and understand holiday-aware schedules.

  • Date Calculator

    Add or subtract days and compare dates when the task is plain calendar math.

  • Countdown

    Track the time remaining until a date or event.

  • Holiday Countdowns

    Days until Christmas, Easter, Thanksgiving, Ramadan, Diwali, and other dates people plan around.

Use year and day references

  • Day of the Year

    Current ordinal day with year progress and practical context.

  • Leap Year

    See how leap years affect annual numbering and date calculations.

  • Julian Date Calendar

    Browse full-year day-number charts for lookup and print use.

Three ways to count the same week

From Monday January 5 to Monday January 12, 2026, seven calendar days pass. Excluding the start date, five of those are weekdays. Counting both Mondays gives eight calendar dates and six weekdays. None of these answers is interchangeable; the counting convention is part of the result.

Weeks do not fit neatly into years

An ordinary year has 52 weeks plus one day, and a leap year has 52 weeks plus two days. ISO week-years have 52 or 53 complete Monday-to-Sunday weeks. January 1 can therefore fall in the previous ISO week-year. Store the week-year with a week number when labeling reports.

Pick the right planning unit

For a reminder 30 dates after today, use the date calculator. For a delivery estimate stated in business days, use the working-day counter and check its holiday setting. For a recurring monthly task, add calendar months: January 31 plus one month is the last day of February under this site’s month-end rule, while January 31 plus 30 days falls in March.