Articles About Calendar (88)
October: Hunter’s Moon
October’s Full Moon is the Hunter’s Moon. It's also called the Drying Rice Moon, Blood Moon, or Sanguine Moon. Every three years or so, it's also the Harvest Moon.
The 7 Days of the Week
The 7-day week is the international standard that is used by the majority of the world. There are 52 or 53 weeks in a year, but countries vary on how they count the weeks.
Full Moon Names
Ancient cultures gave names to the Full Moon. These names are still in use today.
The Full Moon
The third primary phase of the Moon is the Full Moon.
What Is a Leap Year?
A leap year has 366 days, as opposed to a common year, which has 365. Nearly every four years is a Leap Year, and we add a leap day, an extra day on February 29.
The Gregorian Calendar
The Gregorian calendar is the internationally accepted civil calendar that was first adopted in 1582.
The New Moon
When is the next New Moon? New Moon is when the Sun and Moon are aligned, with the Sun and Earth on opposite sides of the Moon.
How Does the Mayan Calendar Work?
The Maya calendar consists of a system of three interlacing calendars and almanacs which was used by several cultures in Central America, most famously the Maya civilization.
The Chinese Calendar
The Chinese calendar is one of the oldest calendars still in use.
The Julian Calendar
The Julian calendar reformed the ancient Roman calendar and consists of three cycles of 365-day years followed by a 366-day leap year. Introduced by and named after Julius Caesar in 45 BCE.
What Do CE and BCE Mean?
CE is an abbreviation for Common Era and BCE is short for Before Common Era.
What Is a Blue Moon?
“Once in a blue moon” suggests something is very rare. But just how rare is a Blue Moon?
June Solstice
The June solstice is the longest day of the year in the Northern Hemisphere and the shortest day in the Southern Hemisphere.
Calculating the Easter Date
The date of Easter Day depends on age-old approximations of the Full Moon and the March equinox.
The Month of October
October is the tenth month of the year and has 31 days. It was originally the eighth month of the Roman calendar until 153 BCE.
The Harvest Moon 2023
The Harvest Moon varies between September or October in the Northern Hemisphere. It is the Full Moon nearest the autumnal (fall) equinox.
First Quarter Moon
The 1st Quarter Moon is a primary Moon phase when we can see exactly half of the Moon's surface lit up. Which half depends on where you are on Earth.
Leap Day February 29
When is the next Leap Year? A Leap Year consists of 366 days – not 365 – where February 29 is added as an extra day at the end of February.
The Islamic Calendar
Muslims around the world use the Hijri calendar. How does it work?
Gregorian Calendar Reform: Why Are Some Dates Missing?
The Gregorian calendar was introduced in 1582 in some countries. The US, Canada, and the UK changed in 1752. Why were some days skipped?
The Roman Calendar
The Roman calendar is is the grandfather of our modern calendar.
Third Quarter Moon
The Third or Last Quarter Moon is when the opposite half of the Moon is illuminated compared to the First Quarter.
The 823-Year Myth
5 Fridays, 5 Saturdays, and 5 Sundays in the same month happens only every 823 years? This popular urban myth is precisely that: a myth.
November: Beaver Moon
The Full Moon in November is named after beavers. It is also called Frost Moon and Mourning Moon, depending on the winter solstice.
Monday: the Moon’s Day
Monday is the first day of the week according to the international standard, but in the US, Canada, and Japan it is the second day of the week.
What Are Palindrome Days?
A palindrome day is when the day’s date can be read the same way backward and forward. The dates are similar to word palindromes in that they are reversible. When is the next palindrome date?
The Ethiopian Calendar
The Ethiopian calendar is similar to the Julian calendar.
Why Does a Week Have 7 Days?
It's Monday, you have to wait 5 days till the weekend. Why does a week have 7 days, and why in that order? Thank the Moon and an ancient people in today's Iraq.
The Jewish Calendar
Jews worldwide use this calendar. Find out how it works.
How Accurate Are Calendars?
Our calendar does not accurately reflect the length of a tropical year, the time it takes Earth to complete a full orbit around the Sun. Why is that so and are there other calendars that do a better job?
What Is a Black Moon?
A Black Moon can be the third New Moon in a season with four New Moons or the second New Moon in the same calendar month, or even no New Moon at all.
When Did the 21st Century Start?
When did the 3rd millennium and 21st century begin: on New Year's Day 2000 or 2001? Do we count from year 1 or year 0 AD? What century are we in?
11/11/11 – a date with a special meaning?
The meaning of dates, such as 11/11/11, is becoming more popular since the start of the new millennium.
What is a Common Year?
A common year is a calendar year with 365 days and only 28 days in February.
The Month of January
January has 31 days, and is named after the two-faced Roman god Janus.
Waning Crescent Moon
During the Waning Crescent Moon phase, the lit-up part of the Waning Moon shrinks from the Third Quarter Moon until it disappears from view at New Moon.
February 30
February 30 actually existed at least twice in the past, according to historical records.
The Doomsday Algorithm - Calculating the Weekday of any given Date
Some dates fall on the same weekday every year. Use this knowledge to calculate the weekday of any date in your head.
The Month of February
February is the second month of the year in the Gregorian calendar. It is the shortest month with only 28 days in common years and 29 days in leap years.
The Month of November
November is the 11th month of the year and has 30 days. It was originally the 9th month of the Roman calendar until 153 BCE.
Thursday Is Thor's Day
Thursday is named after Thor, the hammer-wielding Norse god of thunder. It is the fourth day of the week between Wednesday and Friday.
January: Wolf Moon
January's Full Moon is named after howling wolves. In some cultures, it's known as the Quiet Moon, Severe Moon, and the Moon after Yule.
Leap Day Customs
Learn more about Leap Day traditions, superstitions and folklore.
What Is a Lunar Month?
A lunar month is the time it takes the Moon to pass through all of the Moon phases, usually measured from a New Moon the next New Moon.
The Month of September
September is the ninth month of the year in and has 30 days. It was originally the seventh month of the Roman calendar until 153 BCE.
The Doomsday Rule
Some dates fall on the same weekday every year. Use this knowledge to calculate the weekday of any given date in your head.
Sunday: the Sun's Day
Sunday is the seventh day of the week according to the international standard. However, many countries count Sunday as the first day of the week.
Special Calendar Dates
Learn more about numerically unique calendar dates such as sequential dates, same number dates, and palindrome (reversible) dates
The Month of August
August is the eighth month in the Gregorian calendar and has 31 days. In the northern half of the world, August is the last month of summer.
The Month of March
March is the third month of the year. It has 31 days and is named after Mars, the Roman god of war.
The Month of December
December is the twelfth month of the year and has 31 days. It was originally the tenth month of the Roman calendar until 153 BCE.
The Buddhist Calendar
Buddhists use a lunisolar calendar system. How does it work?
December: Cold Moon
The December Full Moon is called the Cold Moon, Long Nights Moon, the Moon before Yule, Oak Moon, and Wolf Moon.
Anniversary and Birthday Traditions Around the World
Anniversaries and birthdays are celebrated differnetly in different cultures around the world.
August: Sturgeon Moon
The Full Moon in August is called the Sturgeon Moon, named after North America’s largest fish. Other names for this Full Moon include Grain Moon, Corn Moon, Lynx Moon, and Lightning Moon.
The Month of June
June is the sixth month of the year, has 30 days, and is named after the Roman goddess Juno.
The Revised Julian Calendar
The Revised Julian calendar is one of the most accurate calendar systems ever developed. How does it work, and why don't we use it?
The Month of July
July is the seventh month of the year, has 31 days, and is named after Julius Caesar.
Wednesday: Odin's Day
Wednesday is the third day of the week, and it is named after Odin, the Norse allfather-god who sent his ravens to Earth to keep an eye on people.
The Month of April
The month of April explained. How many days are in April? Why is April the 4th month? What meaning and symbolism does it have?
Leap Day Birthdays
When do “leaplings” celebrate their birthdays and when can they legally buy alcohol or get a driver's licence?
Tuesday: Tiw’s and Mars' Day
Tuesday was originally named after the Roman god of war Mars, but the Norse people named it after their own god of war, Tyr.
What Are Week Numbers?
Most of us have learned that a year has 52 weeks. So why do some calendars have a week numbered 53?
A Year Is Never 365 Days
The definition of a tropical year is the time it takes the Earth to complete a full orbit around the Sun. It is approximately 365.242189 days long.
Friday Is the Fifth Day
Friday is the fifth day of the week, and the last day of the working week in most western countries. It is named after Norse fertility goddess Frigg.
Saturday: Saturn's day
Saturday is the day of the week, and it is usually considered the sixth day of the week. Saturday is named after the ancient Roman god Saturn.
The Month of May
May is the fifth month of the year, has 31 days, and is likely named after the Greek goddess Maia.
The Jewish Leap Year
The Jewish leap year has 13 months and occurs 7 times in a 19-year cycle.
Long Weekends in the US and the UK
A long weekend happens when a holiday falls right before or after the weekend (e.g., Friday or Monday). Find a list of recurring UK and US long weekends.
March: Worm Moon
The Full Moon in March is the Worm Moon, but if it occurs on or after March 21 it is also the Paschal Moon. It's also called Lenten, Crow, Crust, Chaste, Sugar, and Sap Moon.
September: Harvest and Corn Moon
The September Full Moon can be both the Harvest Moon and the Corn Moon. Most years, the Harvest Moon is in September, but around every three years, it’s in October.
February: Snow Moon
The February Full Moon is named after the snow on the ground. Some Native American tribes named this the Hunger Moon, others call it the Storm Moon.
April: Pink Moon
The Pink Moon is the Full Moon in April. It is also called Breaking Ice Moon, Budding Moon, Awakening Moon, Egg Moon, and Paschal Moon. When is the Pink Moon?
Did the Mayan Calendar Predict The End?
The Mayan calendar ended one of its great cycles in December 2012, which has fueled countless predictions about the end of the world on December 21, 2012 at 11:11(UTC).
June Solstice Traditions
In many Northern Hemisphere cultures, the June solstice is associated with holidays, feasts and celebrations.
June: Strawberry Moon
What is a Strawberry Moon, also called Rose Moon? When is the next Strawberry Full Moon in 2024, why does it happen in June, and how did it get its name?
May: Flower Moon
The Full Moon in May is known as the Flower Moon or Full Flower Moon. Other names include Milk Moon and Hare Moon. What is the meaning behind these names?
Chinese Leap Month
Instead of adding one leap day on February 29 nearly every four years, the Chinese add a leap month every three years to keep their calendar in line with the Earth's rotation.
July: Buck Moon
The Full Moon in July is the Buck Moon. It is also called Thunder Moon, Hay Moon, and Wyrt Moon.
The Coptic Calendar
The Coptic calendar is linked to the ancient Egyptian calendar and the Julian calendar. It is used in Egypt and in the Coptic Church. How does it work?
Leap Months and Leap Days in the Hindu Calendar
The Hindu calendar frequently adds or omits months or days to keep its lunar and solar time reckoning in sync. The concept differs from the western leap year.
The Islamic Leap Year
A leap year in the tabular version of the Islamic Hijri calendar occurs 11 times in a 30-year cycle when one day is added to the last month of the year.
The Ethiopian Leap Year
A leap year occurs every 4 years in the Ethiopian calendar when one extra day is added at the end of the year.
Leap Year in Different Calendars
Most western countries use the Gregorian calendar, but some use other calendars. Some calendars even add a leap month instead of a leap day.
The Persian Leap Year
The Iranian or Persian calendar is one of the most accurate calendar systems ever devised. Find out what makes it so precise.
The Buddhist Leap Year
Following the metonic cycle, the Buddhist calendar defines some years as leap years with 13 months. Great leap years have another extra day.
Bahá'í Leap Years
How do leap years in the Bahá'í Calendar work?
When Do Decades Start?
Did the year 2020 mark the beginning of a new decade, or did the twenties begin on January 1, 2021?