1% Generated by roxygen2: do not edit by hand
2% Please edit documentation in R/timespans.r
3\name{timespan}
4\alias{timespan}
5\alias{timespans}
6\title{Description of time span classes in lubridate}
7\description{
8A time span can be measured in three ways: as a duration, an interval, or a
9period.
10\itemize{
11\item \link{duration}s record the exact number of seconds in a time span.
12They measure the exact passage of time but do not always align with
13human measurements like hours, months and years.
14\item \link{period}s record the change in the clock time between two date-times.
15They are measured in human units: years, months, days, hours, minutes,
16and seconds.
17\item \link{intervals} are time spans bound by two real date-times. Intervals can be
18accurately converted to periods and durations.
19}
20}
21\examples{
22duration(3690, "seconds")
23period(3690, "seconds")
24period(second = 30, minute = 1, hour = 1)
25interval(ymd_hms("2009-08-09 13:01:30"), ymd_hms("2009-08-09 12:00:00"))
26
27date <- ymd_hms("2009-03-08 01:59:59") # DST boundary
28date + days(1)
29date + ddays(1)
30
31date2 <- ymd_hms("2000-02-29 12:00:00")
32date2 + years(1)
33# self corrects to next real day
34
35date3 <- ymd_hms("2009-01-31 01:00:00")
36date3 + c(0:11) * months(1)
37
38span <- date2 \%--\% date  #creates interval
39
40date <- ymd_hms("2009-01-01 00:00:00")
41date + years(1)
42date - days(3) + hours(6)
43date + 3 * seconds(10)
44
45months(6) + days(1)
46}
47\keyword{chron}
48\keyword{classes}
49