Age Calculator

Age Calculator is based on the common age system. In this system, age grows approximately at the day of birth. For example, the age of a person that has lived for 3 years and 11 months is 3 and the age will turn to 4 at his/her next birthday one month later. Most western countries use this age system.

NOTE:
The age of a person can be counted differently in different cultures. Calculate All uses time difference to calculate age, hence converting it to date format for easier readability and understanding. Moreso, ages are further calculated and rounded up to definite values as years, months and days.

In some cultures, age is expressed by counting years with or without including the current year. For example, one person is twenty years old is the same as one person is in the twenty-first year of his/her life. In one of the traditional Chinese age systems, people are born at age 1 and the age grows up at the Traditional Chinese New Year instead of birthday. For example, if one baby was born just one day before the Traditional Chinese New Year, 2 days later the baby will be at age 2 even though he/she is only 2 days old.

In some situations, the months and days result of this age calculator may be confusing, especially when the starting date is the end of a month. For example, we all count April. 20 to May 20 to be one month. However, there are two ways to calculate the age from Feb. 28, 2015 to Mar. 31, 2015. If thinking Feb. 28 to Mar. 28 as one month, then the result is one month and 3 days. If thinking both Feb. 28 and Mar. 31 as the end of the month, then the result is one month. Both calculation results are reasonable. Similar situations exist for dates like June. 30 to July 31, May 30 to June 30, etc. The confusion comes from the uneven number of days in different months. In our calculation, we used the former method.

In many parts of the world an individual's birthday is celebrated by a party where a specially made cake, usually decorated with lettering and the person's age, is presented. The cake is traditionally studded with the same number of lit candles as the age of the individual, or a number candle representing their age. The celebrated individual will usually make a silent wish and attempt to blow out the candles in one breath; if successful, a tradition holds that the wish will be granted. In many cultures, the wish must be kept secret or it won't 'come true'. Presents are bestowed on the individual by the guests appropriate to their age. Other birthday activities may include entertainment (sometimes by a hired professional, i.e. a clown, magician, or musician), and a special toast or speech by the birthday celebrant. The last stanza of Patty Hill's and Mildred Hill's famous song, 'Good Morning to You' (unofficially titled 'Happy Birthday to You') is typically sung by the guests at some point in the proceedings. In some countries a piñata takes the place of a cake.

Official birthdays

Some notables, particularly monarchs, have an official birthday on a fixed day of the year, which may not necessarily match the day of their birth, but on which celebrations are held. Examples are:

• Jesus Christ's traditional birthday is celebrated as Christmas Eve or Christmas Day around the world, on December 24 or 25, respectively. As some Eastern churches use the Julian calendar, December 25 will fall on January 7 in the Gregorian calendar. These dates are traditional and have no connection with the actual birthday date of Jesus, which is not recorded in the Gospels
• Similarly, the birthdays of the Virgin Mary and John the Baptist are liturgically celebrated on September 8 and June 24, especially in the Roman Catholic and Eastern Orthodox traditions (although for those Eastern Orthodox churches using the Julian calendar the corresponding Gregorian dates are September 21 and July 7 respectively). As with Christmas, the dates of these celebrations are traditional and probably have no connection with the actual birthdays of these individuals.
• The Queen's Official Birthday in Australia, Fiji, Canada, New Zealand, and the United Kingdom.
• The Grand Duke's Official Birthday in Luxembourg is typically celebrated on June 23. This is different from the monarch's actual date of birth, which is on April 16.
• Koninginnedag in the Kingdom of the Netherlands was typically celebrated on April 30. Queen Beatrix fixed it at the birthday of her mother, the previous queen, to avoid the winter weather associated with her own birthday in January. The present monarch's birthday is 27 April, and is also celebrated on that day and has replaced the 30th of April celebration of Koninginnedag.
• The previous Japanese Emperor Showa (Hirohito)'s birthday was April 29. After his death, the holiday was kept as "Showa no Hi", or "Showa Day". This holiday falls close to Golden Week, the week in late April and early May.
• Kim Il-sung and Kim Jong-Il's birthdays are celebrated in North Korea as a national holiday.
• Washington's Birthday, commonly referred to as Presidents' Day, is a federal holiday in the United States that celebrates the birthday of George Washington. President Washington's birthday is observed on the third Monday of February each year. However, his actual birth date was either February 11 (Old Style), or February 22 (New Style).
• In India, every year October 2 which marks the Birthday of Mahatma Gandhi, is declared as a holiday. All the liquor shops are closed across the country in honour of Gandhi not consuming liquor.
• Martin Luther King, Jr. Day is a federal holiday in the United States marking the birthday of Martin Luther King, Jr. It is observed on the third Monday of January each year, which is around the time of King's birthday, January 15.
• Mawlid is the official birthday of Muhammad and is celebrated on the 12th or 17th day of Rabi' al-awwal by adherents of Sunni and Shia Islam respectively. These are the two most commonly accepted dates of birth of Muhammad.

According to a public database of births, birthdays in the United States are quite evenly distributed for the most part, but there tend to be more births in September and October. This may be because there is a holiday season nine months before (the human gestation period is about nine months), or because the longest nights of the year also occur in the Northern Hemisphere nine months before. However, it appears the holidays have more of an effect on birth rates than the winter: New Zealand, a Southern Hemisphere country, has the same September and October peak with no corresponding peak in March and April. The least common birthdays tend to fall around public holidays, such as Christmas, New Year's Day and fixed-date holidays such as July 4 in the US.

Based on Harvard University research of birth records in the United States between 1973 and 1999, September 16 is the most common birthday in the United States and December 25 the least common birthday (other than February 29, because of leap years). In 2011, October 5 and 6 were reported as the most frequently occurring birthdays.

In New Zealand, the most common birthday is September 29, and the least common birthday is December 25. The ten most common birthdays all fall within a thirteen-day period, between September 22 and October 4. The ten least common birthdays (other than February 29) are December 24–27, January 1–2, February 6, March 22, April 1 and April 25. This is based on all live births registered in New Zealand between 1980 and 2017.

According to a study by the Yale School of Public Health, positive and negative associations with culturally significant dates may influence birth rates. The study shows a 5.3% decrease in spontaneous births and a 16.9% decrease in Caesarean births on Halloween, compared to dates occurring within one week before and one week after the October holiday. In contrast, on Valentine's Day there is a 3.6% increase in spontaneous births and a 12.1% increase in Caesarean births.

NOTE: The above mentioned birthdays are not reliable or 100% proven and accurate. These contents are available only for the better understanding of age calculation.

Birthday celebration in itself has a queer origin. Further research on this subject is encouraged on your part.