Year guides and calendar explanations

Clear answers about the calendar year, from leap-day rules to practical annual planning.

How much of the year has passed?

Calculate the exact percentage of the current year that is complete.

Find the number of calendar days between today and New Year's Day.

Understand ordinal dates and find today's position in the year.

Why a year is about 52 weeks and why some ISO years have week 53.

See which months belong to Q1, Q2, Q3 and Q4.

Learn the Gregorian leap-year rule and why February sometimes has 29 days.

Estimate weekdays, then account for holidays and leave.

Turn remaining calendar time into a realistic annual plan.

A precise formula for calculating year progress in code or a spreadsheet.

Understand what a New Year countdown measures and how to calculate it.

Compare January-to-December years with alternative twelve-month reporting periods.

How meteorological and astronomical seasons relate to calendar dates.