Day Date Time Calculator

To calculate the number of days since you were born, simply enter your date of birth as the start date and then ensure that the end date is set to today's date (if it isn't already set, click the 'today' link that appears to the right of the box). Then click the 'Calculate' button. Alternatively, you could give my age calculator a try. A date calculator is an automated program used to add or subtract time to or from a specified date. Date calculators use programming functions and formulas to calculate time before or after a chosen date. Information processed using our date calculator Past or future date after calculation. Calculator Input date and time in the left boxes, choose the operator in the middle, enter numbers of time units in the right boxes, and click the 'Calculate' button. Start Date &/Or Time. Date Time Calculator to Add or Subtract Time Spans To/From Dates This date and time calculator will subtract or add days, weeks, months, years, hours, minutes, and seconds from or to the date and time you select.

Calculating Birth Dates[edit | edit source]

We all know that having birth dates helps us to complete the information for our ancestors and birth dates many times are much harder to find the further back you go. But many times we at least have the date of death with the age listed in Years-months-days.

This information can be found on

So how does one calculate a date to get as close as possible to the date of birth? By using a Date Calculator.

• The way to use it is to put in the date of death. Subtract the number of Years, Months, (weeks if given), Days; then click the calculate button. The answer is under the lower left corner under the colored box.
  

• If for some reason you have the Date of Birth and have the number of Years/Months/Days when died you would put in the date of birth click Add followed by the number of years/Months/(weeks)/days then click calculate to get the date of death.
  

• If you want to calculate and age use the Duration Between Two Dates Calculator
  

The Following is an example of a Date Calculator that is on the Date and Time web page, click on the picture or on the link that is just below the picture to go to a live calculator, have fun doing your own calculating of Dates. (there are other types of Calculators on this page)

online Date Calculator website If a pink box shows up just x it)

To discover additional Date calculator links and tips: click here

Other online calculators[edit | edit source]

Tips[edit | edit source]

• Be aware that some of these Websites have other types of calculators with different functions, explanations and tips, with various kinds of information. So check out the rest of the page. (The following examples are what you might find for tips)

• Some calculators may require you to put a 0 in a box instead of leaving a box blank, also using a 0 in front of a single digit month may or may not be required.

• Due to possible errors or different methodology used in Calculated dates from original calculations. (found on the tombstone, obituary or death certificates) , please make a note in your records that the date was calculated..

• The calculator could also be used to calculate birth year from census data or birth date from wedding date and age.

• When calculating Dates using the Julian or Gregorian Calendar you can't use the two together.

• There is what is called a 30-day-month/or **8870 method which assumes that all months have 30 days, many of the headstones and obituary ages at death appear to have been computed using this method. It's an approximation which agrees with the exact calendar month method about 2/3 of the time.) ^[1]

• Because of the change from the Julian to the Gregorian Calendar, the calculator may not work for anyone born between Sept. 2, 1752 and Sept. 14, 1752 or when days were lost at the calendar changeover.^[2]

• Be aware the calendar was changed from Julian to Gregorian in which ever country for which you are performing the calculation. See the change from Julian to Gregorian calendar Dates by country.^[3]

How to calculate by hand[edit | edit source]

When the online calculator is not available, use the **8870 formula or the 30 day month length ^[4]

For example:If a person died May 6, 1889 at age 71 years, 7 months and 9 days:

18890506Year, day, month of death (yyyymmdd)1889--05--06

_________ 18179797

________18170927 Born 27 Sept. 1817 (yyyymmdd)1817yr-09mo-27dd

This person was born on September 27, 1817

References[edit | edit source]

1. ↑Ancestor search
2. ↑Ancestor search
3. ↑Ancestor search
4. ↑Search for ancestors

Days Between Two Dates

Find the amount of years, months, weeks, and days between dates. Click 'Settings' to define holidays.

Add to or Subtract from a Date

History of the Gregorian Calendar

The Gregorian calendar is the most prevalently used calendar today. Within this calendar, a standard year consists of 365 days with a leap day being introduced to the month of February during a leap year. The months of April, June, September, and November have 30 days, while the rest have 31 days except for February, which has 28 days in a standard year, and 29 in a leap year.

The Gregorian calendar is a reformed version of the Julian calendar, which was itself a modification of the ancient Roman calendar. The ancient Roman calendar was believed to be an observational lunar calendar, based on the cycles of the moon's phases. The Romans were then believed to have adopted a 10-month calendar with 304 days, leaving the remaining 50 or so days as an unorganized winter. This calendar allowed summer and winter months to become completely misplaced, leading to the adoption of more accurate calendars.

Time Calculator Months Days

The Republican calendar later used by Rome followed Greek calendars in its assumptions of 29.5 days in a lunar cycle, and 12.5 synodic months in a solar year, which align every fourth year upon the addition of the intercalary months of January and February. From this point, many attempts were made to align the Republican calendar with the solar year including the addition of an extra month to certain years to supplant the lack of days in a particular year. In 46 BC, the calendar was further reformed by Julius Caesar, introducing an algorithm that removed the dependence of calendars from the observation of the new moon. In order to accomplish this, Caesar inserted an additional 10 days to the Republican calendar, making the total number of days in a year 365. He also added the intercalation of a leap day every fourth year, all in an attempt to further synchronize the Roman calendar with the solar year.

Despite all efforts, the Julian calendar still required further reform, since the calendar drifted with respect to the equinoxes and solstices by approximately 11 minutes per year. By 1582, this resulted in a difference of 10 days from what was expected. Pope Gregory XIII addressed this by essentially skipping 10 days in the date, making the day after October 4, 1582, October 15. An adjustment was also made to the algorithm of the Julian calendar that changed which century years would be considered leap years. Under the Gregorian calendar, century years not divisible by 400 would not be leap years. These changes reduced the error from 1 day in 128 years, to 1 day in 3,030 years with respect to the current value of the mean solar year.

The adoption of the Gregorian calendar occurred slowly over a period of centuries, and despite many proposals to further reform the calendar, the Gregorian Calendar still prevails as the most commonly used dating system worldwide.

Holidays

A holiday is a day that, either by custom or by law, is set aside such that regular activities like going to work or school is suspended, or at least reduced. The term 'holiday' can be interpreted differently, depending on region. In the U.S. paid leave is typically referred to as 'vacation,' while national, religious, or cultural days off are referred to exclusively as 'holiday.' In some regions however, such as the United Kingdom or former British colonies, the term holiday can also refer to paid leave.

Generally, holidays are meant to commemorate some event, person, or group of cultural or religious significance. Although certain holidays, such as Christmas and New Year's Day, are widely celebrated worldwide, most countries have their own set of holidays that are specific to the country, and even the same holidays may be observed differently within countries: some may receive full suspension of typical daily activities, while others may only get partial days off. Certain countries have holidays that essentially shut down almost all businesses. As an example, in Brazil, Carnaval do Brasil results in almost a full week in which only industrial production, retail establishments, or carnival-related businesses, function.

This calculator is mainly geared towards U.S. holidays, but holidays specific to a given country can be entered manually. Certain holidays can also be excluded. For a further level of specificity, federal holidays in the U.S. refer to holidays that have been recognized by the U.S. government; on these days, non-essential federal government offices are closed, and all federal employees receive paid leave. This is not necessarily true in the private-sector however, and which federal holidays a private-sector employee receives is largely dependent on the discretion of the company. In some cases, an employee who is required to work on a federal holiday may receive compensation in the form of holiday pay in addition to their regular wages.

Certain holidays such as New Year's Day are referred to as 'fixed holidays,' since they fall on the same date every year. Others such as the birthday of Martin Luther King, Jr., don't have a fixed date, because they occur on a 'floating Monday'; in this particular case, the holiday occurs on the third Monday of January. Another widely observed holiday in the U.S., Thanksgiving, occurs on a 'floating Thursday,' the fourth Thursday In November, hence the dates of these holidays vary by year. Below are two tables showing the dates of federal holidays in the U.S. for 2021 and 2022.

Cached

2021 U.S. Federal Holidays

How To Calculate The Number Of Days Between Two Dates In Excel

2022 U.S. Federal Holidays

Date Duration Calculator: Days Between Dates