Articles About Dates (21)
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.
The Gregorian Calendar
The Gregorian calendar is the internationally accepted civil calendar that was first adopted in 1582.
What Do CE and BCE Mean?
CE is an abbreviation for Common Era and BCE is short for Before Common Era.
Calculating the Easter Date
The date of Easter Day depends on age-old approximations of the Full Moon and the March equinox.
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.
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?
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.
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.
February 30
February 30 actually existed at least twice in the past, according to historical records.
Friday the 13th Facts
13 facts about Friday the 13th, the unluckiest day in the Gregorian calendar.
Leap Day Customs
Learn more about Leap Day traditions, superstitions and folklore.
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.
Special Calendar Dates
Learn more about numerically unique calendar dates such as sequential dates, same number dates, and palindrome (reversible) dates
12/12/12 - Special Date Pattern
December 12, 2012 or 12-12-12 was the last date of its kind - when all three numericals in a date were the same - for 88 years. The next time this will happen is on January 1, 2101, or 01-01-01.
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.
When Do Decades Start?
Did the year 2020 mark the beginning of a new decade, or did the twenties begin on January 1, 2021?
99% of Earthlings See Sunlight on July 8 (And on Other Dates, Too)
Our Sun data confirm an internet meme claiming 99% of the world’s population gets sunlight at 11:15 UTC on July 8. But does it happen on other dates, too?
99% Of Us See Daylight at This Moment (Or Do We?)
Is it really true that 99% of the world's population see daylight at 11:15 UTC on July 8?
Dec 6: Minute of Global Darkness
There's a moment each year when almost 9 in 10 people worldwide experience night.
When Is Mother’s Day, Really?
When is Mother's Day? Why are there different dates for different countries? Who celebrates when? An overview of Mother's Day around the world.