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# Special Calendar Dates

## Unique Calendar Dates

An array of interesting dates come with the new millenium.

The start of the new millennium began the introduction of interesting dates depending on its date order format. Many find that calendar dates such as repeating dates like January 1, 2001 (01/01/01), palindrome (reversible) dates like January 02, 2010 (01/02/2010), repetitive dates like October 20, 2010 (20/10/2010) and sequential dates like January 02, 2003 (01/02/03) all have a significant characteristic that makes them unique and interesting, and even hold a deeper meaning.

However, the world has many date order formats that are used to write down the numerical form of calendar dates that can cause confusion when used in international correspondence, especially when the year is abbreviated into its final two digits. Some of the common formats are:

• Month/Day/Year - MM/DD/YYYY - Mostly used in North America.
• Day/Month/Year - DD/MM/YYYY - Mostly used in the European languages.
• Year/Month/Day - YYYY/MM/DD - Mostly used in the Chinese language.

It is also important to note that the two-digit number for the day and month can be represented by a single one-digit number if it is between the numbers one (1) and nine (9). Moreover, the four-digit number for the year may be represented by a two-digit number.

In general, the years 2000 - 2012 have many interesting patterns in the calendar date, unlike the 1990s that didn’t have many options because minutes and seconds end at 59, the calendar day ends at 28 and 31, and the calendar month ends at 12.

## Repeating Dates

Repeating dates of the same sequence or number has become more common since the year 2001, especially since the year can be abbreviated into the last two-digits. The year 2011 holds many interesting dates such as January 1, 2011 (01/01/11 or 1.1.11) where the date can be read the same in both date order formats (MM/DD/YY or DD/MM/YY).

The year 2011 will have many interesting repeating dates such as January 11, 2011 (1.11.11), November 1, 2011 (11.1.11) and November 11, 2011 (1.11.11). These dates only consist of the number one and may cause some confusion when written in its numerical form.

The calendar date can also be read in a repeating sequence such as a sequence of three numbers that are repeated twice or a sequence of four numbers that are repeated twice. For example, in the date order format of MM/DD/YY the date of 10/31/03 consists of a sequence of three numbers (1-0-3) that is repeated twice (103-103).

In the format of DD/MM/YY, the date of October 20, 2010 has an interesting sequence in which the numerical abbreviation is 20/10/2010. This sequence consists of four numbers (2-0-1-0) that are repeated twice (2010-2010). These dates will become more seldom after the year 2013 because the number 13 is not a valid month.

## Palindrome Calendar Dates

Palindrome calendar dates are dates that can be read backward and forward (symmetrical) in its numerical date format. These types of dates can have many variations due to the many types of date order format.  The most common date order format used to find palindrome dates is M(M)/(D)D/YYYY where it allows you to use a single digit (when applicable) for the month and day.

There are some dates that have more than one palindromic form such as September 29, 1929. This date can be written in three different ways:

• Without the year - 9/29 (9-2-9)
• With the year abbreviated - 9/29/29 (9-2-9-2-9)
• With the full year - 9/29/1929 (9-2-9-1-9-2-9)

## Sequential Calendar Dates

Sequential calendar dates occur when the date is read in a sequence, whether it is increasing or decreasing. The first sequential day in more than twenty years occurred on August 9, 2010 at 12:34:56.7pm. This day was known as Sequential day because the rare numerical phenomenon where the time and date read 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 if read as 12:34:56.7pm 08/09/10. However this only occurred for areas that read the date in the format of MM/DD/YY, otherwise this phenomenon would occur on September 8, 2010, if the date format is read as DD/MM/YY.

## The Date Pattern Calculator

You can find out more interesting dates using our newest service, the Date Pattern Calculator. This new calculator will show the unique patterns that a single calendar date can create, as well as the different patterns in a given month or year. You can discover sequential dates, dates that consist of one number, as well as calendar dates that are symmetrical or can be read upside-down.

Now you can find out when the calendar date is equal to Pi (March 14, 2015 or 3/14/15) or when it’s equal to E (February 7, 2018 - 2/7/18 or July 2, 2018 - 2/7/18). Some may even go further to find out the square root of 2 day (January 14, 2042 or 14/1/42). It is a very useful tool for all date and number enthusiasts.