Calendar Guides & Articles
Short, practical guides to making, printing, and understanding calendars. Learn which printable calendar type fits your needs, how to print a calendar PDF in under a minute, which paper size to choose, how many weeks are in a year, and how to read a moon phase calendar. Everything here is free, with no sign-up, and every guide links straight to the calendar generator so you can put it into practice.
For the numbers and structure behind the calendar, see how many days are in a year, the Julian date and day-of-year reference, how ISO week numbers work, and what a perpetual calendar is.
Moon Phase Calendar Explained: New Moon, Full Moon & How to Read One
A moon phase calendar shows the Moon's shape for each day. Learn the 8 phases, the 29.5-day cycle, the difference between waxing and waning, and how to read and print one for any month.
What Is a Perpetual Calendar?
A perpetual calendar works for any year, because every Gregorian year matches one of 14 layouts set by the January 1 weekday and leap status. See how they work and print any year from 2001 to 2051.
ISO Week Numbers Explained
ISO 8601 week numbers run Monday to Sunday, with week 1 fixed to the year's first Thursday. Here is the rule, how ISO differs from US week numbering, and how to switch on week numbers in the generator.
How Many Days Are in a Year? (365, 366, and Leap Years)
A common year has 365 days and a leap year 366. Here is the leap-year divisible-by-4/100/400 rule, a worked table of which years are leap years, the days in each month, and the working-days count.