http://pl.wikipedia.org/wiki/Kalendarz
Kalendarz – umowna, przyjęta w danej społeczności bądź kulturze, rachuba czasu. Dzieli ona czas na powtarzające się cyklicznie okresy, związane najczęściej z cyklami przyrody. Nazwa pochodzi od rzymskiego słowa Kalendy bądź według innych źródeł od łacińskiego callendarium. Obecnie najbardziej rozpowszechnionym kalendarzem na świecie jest kalendarz gregoriański – wprowadzony 15 października 1582 przez papieża Grzegorza XIII i oparty na długości roku zwrotnikowego.
(…)
http://pl.wikipedia.org/wiki/Kalendarz_starogrecki
Kalendarz starogrecki – był to kalendarz księżycowy lub księżycowo-słoneczny, jednak kalendarze poszczególnych państw-miast różniły się między sobą. Inne były nazwy, rok zaczynał się z inną datą, inaczej przeprowadzano interkalację i inaczej liczono lata. Często bardzo trudne jest ustalenie, jakiemu miesiącowi w jednym państwie odpowiada dany miesiąc w drugim.
http://en.wikipedia.org/wiki/Byzantine_calendar
The calendar is based on the Julian calendar except that the year started on 1 September.
http://en.wikipedia.org/wiki/Julian_calendar
The Julian calendar, introduced by Julius Caesar in 46 BC (708 AUC), was a reform of the Roman calendar. It took effect in 45 BC (709 AUC). It was the predominant calendar in most of Europe, and in European settlements in the Americas and elsewhere, until it was refined and superseded by the Gregorian calendar.
http://en.wikipedia.org/wiki/Roman_calendar
The Roman calendar changed its form several times between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars. The original Roman calendar is believed to have been a lunar calendar, which may have been based on one of the Greek lunar calendars.[1]
http://en.wikipedia.org/wiki/Hellenic_calendar
The Hellenic calendar—or more properly, the Hellenic calendars, for there was no uniform calendar imposed upon all of Classical Greece—began in most Greek states between Autumn and Winter except the Attic calendar, which began in June.
http://en.wikipedia.org/wiki/Calendar
The English word calendar is derived from the Latin word kalendae, which was the Latin name of the first day of every month.
http://www.britannica.com/EBchecked/topic/89368/calendar
Calendar, any system for dividing time over extended periods, such as days, months, or years, and arranging such divisions in a definite order. A calendar is convenient for regulating civil life and religious observances and for historical and scientific purposes. The word is derived from the Latin calendarium, meaning “interest register” or “account book,” itself a derivation from calendae (or kalendae), the first day of the month in the Roman republican calendar, the day on which future market days, feasts, and other occasions were proclaimed.
http://en.wikipedia.org/wiki/Calends
(…)This word forms the basis of the English word calendar. The Latin term is traditionally written with initial K, following the ancient custom using this letter in a few words beginning with the sequence ka. (…)
http://en.wiktionary.org/wiki/kalendae
Alternative forms: calendae, kalendae. Related terms: kalendālis, kalendārium
Noun kalendae f pl (genitive kalendārum); first declension
Latin The calends, the first day of the month
Inflection First declension.
Number Plural
nominative kalendae
genitive kalendārum
dative kalendīs
accusative kalendās
ablative kalendīs
vocative kalendae
http://roma.andreapollett.com/S7/roma-cal.htm
Kalendae, Nonae, Idus ancient Rome’s dating systems
(…)
MONTHS AND YEARS
A very early attempt of dividing the time elapsed between the cyclic changing of the seasons was a 10-month year, whose total length was 304 days. This scheme, probably already in use by the time of Rome’s foundation, was obviously inaccurate; for this reason, an uncounted number of days was likely added, so that events for which a specific timing was required, such as sowing or gathering the harvest, could be carried out reasonably on time.
The second Roman king, Numa Pompilius (c.700 BC), is traditionally credited for having increased the number of months by two, thus lengthening the year to 355 days. Having this scheme been adopted also during the following Republican Age, up to the 1st century BC, it is now usually referred to as the Roman Republican year.
This year originally started with the month of March (New Year’s Day fell on March 14), probably because early spring is the period in which nature comes to new life again after the cold season. January and February, which had been added shortly earlier, were in fact the last months of the year. Half of the twelve months had names that recalled the gods whom they were sacred to, while others were named after their ordering sequence. (…)
http://www.thefreedictionary.com/Kalendae
cal•ends or kal•ends (ˈkæl əndz)
n.(often cap.) (usu. with a pl. v.) the first day of the month in the ancient Roman calendar. [1325–75; Middle English kalendes < Latin kalendae (pl.), perhaps akin to calāre to proclaim]
http://www.thefreedictionary.com/Calendar
n. cal·en·dar (kăl′ən-dər)
1. Any of various systems of reckoning time in which the beginning, length, and divisions of a year are defined.
2. A table showing the months, weeks, and days in at least one specific year.
(…)
[Middle English calender, from Old French calendier, from Late Latin kalendārium, from Latin, account book, from kalendae, calends (from the fact that monthly interest was due on the calends); see kelə-2 in Indo-European roots.]
http://www.cultusdeorum.org/english/beginner-s-guides/calendar
Important days in the month.
The first day of every month is the Kalends, sacred to Juno.(…)
http://thepaganleft.blogspot.co.uk/2006/01/kalendae-januariae.html
Modern Date : January 1st
Kalendae Januariae/The Kalends of January
This is one of the dies fasti on which legal actions are permitted.
The kalends were the day on which interest payments were due in Rome. In stable economic times the interest rate was 1/2% (per month). January is named for the god Janus, the god of Beginnings. This day, the Kalends, was not originally the first day of the year (it was March 1st), and therefore they had no traditional celebration of this day. On this day the Romans traditionally exchanged strenae (French etrenne), or gifts.In 153 BC E this day became the beginning of the Roman Civil year, when the Consuls entered office. This had previously occurred on March 15th.
(…)