year {lubridate} | R Documentation |
Date-time must be a POSIXct, POSIXlt, Date, Period, chron, yearmon, yearqtr, zoo, zooreg, timeDate, xts, its, ti, jul, timeSeries, and fts objects.
isoyear()
returns years according to the ISO 8601 week calendar.
epiyear()
returns years according to the epidemilogical week calendars.
year(x) year(x) <- value isoyear(x) epiyear(x)
x |
a date-time object |
value |
a numeric object |
year does not yet support years before 0 C.E.
the years element of x as a decimal number
http://en.wikipedia.org/wiki/ISO_week_date http://www.cmmcp.org/epiweek.htm
x <- ymd("2012-03-26") year(x) year(x) <- 2001 year(x) > 1995