The Gregorian calendar is the international standard and is used in most parts of the world to organize religious, social, business, personal, and administrative events. The vague year, from annus vagus or wandering year, is an integral approximation to the year equaling 365 days, which wanders in relation to more exact years. Typically the vague year is divided into 12 schematic months of 30 days each plus 5 epagomenal days. The vague year was used in the calendars of Ethiopia, Ancient Egypt, Iran, Armenia and in Mesoamerica among the Aztecs and Maya. It is still used by many Zoroastrian communities. Astronomical years do not have an integer number of days or lunar months. Any calendar that follows an astronomical year must have a system of intercalation such as leap years.
The Gregorian calendar was a further improvement and has been almost universally adopted because it satisfactorily draws into one system the dating of religious festivals based on the phases of the Moon and seasonal activities determined by the movement of the Sun. Such a calendar system is complex, since the periods of the Moon’s phases and the Sun’s motion are incompatible; but by adopting regular cycles of days and comparatively simple rules for their application, the calendar provides a year with an error of less than half a minute. Once the day is divided into parts, the next task is to gather numbers of days into groups. Among primitive peoples, it was common to count moons (months) rather than days, but later a period shorter than the month was thought more convenient, and an interval between market days was adopted.
- In West Africa some tribes used a four-day interval; in central Asia five days was customary; the Assyrians adopted five days and the Egyptians 10 days, whereas the Babylonians attached significance to the days of the lunation that were multiples of seven.
- It is essential, too, for any civilization that needs to measure periods for agricultural, business, domestic, or other reasons.
- These examples are programmatically compiled from various online sources to illustrate current usage of the word ‘year.’ Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
- There are typically 180 days of teaching each year in schools in the US, excluding weekends and breaks, while there are 190 days for pupils in state schools in Canada, New Zealand and the United Kingdom, and 200 for pupils in Australia.
- The development of a calendar is vital for the study of chronology, since this is concerned with reckoning time by regular divisions, or periods, and using these to date events.
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. A seasonal year is the time between successive recurrences of a seasonal event such as the flooding of a river, the migration of a species of bird, the flowering of a species of plant, the first frost, or the first scheduled game of a certain sport. All of these events can have wide variations of more than a month from year to year.
For example, the Gregorian calendar was adopted in India nationwide when the British colonized the country. Although most of urban India continues to use it today, devout Hindus in more rural parts of the country may continue to use a different regional, religious calendar, where the beginning and end of year dates differ. A calendar era assigns a cardinal number to each sequential year, using a reference event in the past (called the epoch) as the beginning of the era. Individuals who file using the calendar year must continue to do so even if they begin operating a business, sole proprietorship, or become an S corporation shareholder. For the following, there are alternative forms that elide the consecutive vowels, such as kilannus, megannus, etc.
There may also be a voluntary summer session or a short January session. An academic year is the annual period during which a student attends an educational institution. The academic year may be divided into academic terms, such as semesters or quarters.
Example of Calendar Years
The IRS requires businesses to file their taxes on the 15th day of the third month after the end of their fiscal year. So if a company’s fiscal year ends on June 30, the business must file its taxes by September 15. It differs from the sidereal year for stars away from the ecliptic due mainly to the precession of the equinoxes. Some other schools, including some in the United States, have four marking periods.
For example, seasonal businesses that derive the majority of their revenue during a certain time of the year often choose a fiscal year that best matches revenue to expenses. For sole proprietors and small businesses, tax reporting is often easier when the business’s tax year matches up with that of the business owner. Moreover, while any sole proprietor or business may adopt the calendar year as its fiscal year, the IRS imposes specific requirements on those businesses wanting to use a different fiscal year. For individual and corporate taxation purposes, the calendar year commonly coincides with the fiscal year and thus generally comprises all of the year’s financial information used to calculate income tax payable.
The school year in many countries starts in August or September and ends in May, June or July. In Israel the academic year begins around October or November, aligned with the second month of the Hebrew calendar. Historically, lunisolar calendars intercalated entire leap months on an observational basis. Lunisolar calendars have mostly fallen out of use except for liturgical reasons (Hebrew calendar, various Hindu calendars).
Advantages and Disadvantages of a Calendar Year
In most cases, this period starts on April 1 and ends on March 31, and better conforms to seasonality patterns or other accounting concerns applicable to their businesses. These examples are programmatically compiled from various online sources to illustrate current usage of the word ‘calendar.’ Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. These examples are programmatically compiled from various online sources to illustrate current usage of the word ‘calendar year.’ Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Generally, those who follow the calendar year for tax filings include anyone who has no annual accounting period, has no books or records, and whose current tax year does not qualify as a fiscal year.
Measurement of time and types of calendars
In West Africa some tribes used a four-day interval; in central Asia five days was customary; the Assyrians adopted five days and the Egyptians 10 days, whereas the Babylonians attached significance to the days of the lunation that were multiples of seven. In ancient Rome, markets were held at eight-day intervals; because of the Roman method of inclusive numeration, the market day was denoted nundinae (“ninth-day”) and the eight-day week an inter nundium. There was also great variety in the ways in which the day was subdivided. Such seasonal variations in divisions of the day, now called seasonal or temporal hours, became customary in antiquity because they corresponded to the length of the Sun’s time above the horizon, at maximum in summer and at minimum in winter. Only with the advent of mechanical clocks in western Europe at the end of the 13th century did seasonal (unequal) hours become inconvenient. Although days are now measured from midnight to midnight, this has not always been so.
These examples are programmatically compiled from various online sources to illustrate current usage of the word ‘year.’ Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Some schools in the UK, Canada and the United States divide the academic year into three roughly equal-length terms (called trimesters or quarters in the United States), roughly coinciding with autumn, winter, and spring. At some, a shortened summer session, sometimes considered part of the regular academic year, is attended by students on a voluntary or elective basis. Other schools break the year into two main semesters, a first (typically August through December) and a second semester (January through May). Each of these main semesters may be split in half by mid-term exams, and each of the halves is referred to as a quarter (or term in some countries).
Schools and universities in Australia typically have academic years that roughly align with the calendar year (i.e., starting in February or March and ending in October to December), as the southern hemisphere experiences summer from December to February. There are typically 180 days of teaching each year in schools in the US, excluding weekends and breaks, while there are 190 waive vs wave days for pupils in state schools in Canada, New Zealand and the United Kingdom, and 200 for pupils in Australia. You must first obtain approval from the Internal Revenue Service (IRS) by filing Form 1128 if you want to switch from the calendar year reporting to fiscal year reporting for your tax filings. Some parts of the world use the standard as well as religious calendars.
The seven-day week may owe its origin partly to the four (approximately) seven-day phases of the Moon and partly to the Babylonian belief in the sacredness of the number seven, which was probably related to the seven planets. Moreover, by the 1st century bce the Jewish seven-day week seems to have been adopted throughout the Roman world, and this influenced Christendom. The names in English of the days of the week are derived from Latin or Anglo-Saxon names of gods. A calendar year for individuals and many companies is used as the fiscal year, or the one-year period on which their payable taxes are calculated.