Year "year", originally 秂, an ideographic compound of a person carrying a bundle of wheat denoting "harvest". Slavic besides "godŭ" "time period; year" uses "lěto" "summer; year". In the International System of Quantities (ISO 80000-3), the year (symbol, "a") is defined as either 365 days or 366 days. No astronomical year has an integer number of days or lunar months, so any calendar that follows an astronomical year must have a system of intercalation such as leap years. In the Julian calendar, the average (mean) length of a year is 365.25 days. In a non-leap year, there are 365 days, in
Julian calendar falling on 29 August preceding a Julian bissextile day. It was otherwise identical to the Egyptian calendar. The first leap day was in 22 BC, and they occurred every four years from the beginning, even though Roman leap days occurred every three years at this time (see Leap year error). This calendar influenced the structure of several other reformed calendars, such as those of the cities of Gaza and Ascalon in Palestine, Salamis in Cyprus, and the province of Arabia. It was adopted by the Coptic church and remains in use both as the liturgical calendar of the Coptic church