| % File src/library/base/man/round.POSIXt.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2022 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{round.POSIXt} |
| \alias{round.POSIXt} |
| \alias{trunc.POSIXt} |
| \alias{round.Date} |
| \alias{trunc.Date} |
| \title{Round / Truncate Data-Time Objects} |
| \description{ |
| Round or truncate date-time objects. |
| } |
| \usage{ |
| \method{round}{POSIXt}(x, |
| units = c("secs", "mins", "hours", "days", "months", "years")) |
| \method{trunc}{POSIXt}(x, |
| units = c("secs", "mins", "hours", "days", "months", "years"), |
| \dots) |
| |
| \method{round}{Date}(x, \dots) |
| \method{trunc}{Date}(x, |
| units = c("secs", "mins", "hours", "days", "months", "years"), |
| \dots) |
| } |
| \arguments{ |
| \item{x}{an object inheriting from \code{"\link{POSIXt}"} or \code{"\link{Date}"}.} |
| \item{units}{one of the units listed, a string. Can be abbreviated.} |
| \item{\dots}{arguments to be passed to or from other methods, notably |
| \code{digits} for \code{round}.} |
| } |
| \details{ |
| The time is rounded or truncated to the second, minute, hour, day, |
| month or year. Time zones are only relevant to days or more, when |
| midnight in the current \link{time zone} is used. |
| |
| For \code{units} arguments besides \dQuote{months} and \dQuote{years}, |
| the methods for class \code{"Date"} are of little use except to remove |
| fractional days. |
| } |
| \value{ |
| An object of class \code{"POSIXlt"} or \code{"Date"}. |
| } |
| \seealso{ |
| \code{\link{round}} for the generic function and default methods. |
| |
| \code{\link{DateTimeClasses}}, \code{\link{Date}} |
| } |
| |
| \examples{ |
| round(.leap.seconds + 1000, "hour") |
| ## IGNORE_RDIFF_BEGIN |
| trunc(Sys.time(), "day") |
| (timM <- trunc(Sys.time() -> St, "months")) # shows timezone |
| (datM <- trunc(Sys.Date() -> Sd, "months")) |
| (timY <- trunc(St, "years")) # + timezone |
| (datY <- trunc(Sd, "years")) |
| ## IGNORE_RDIFF_END |
| stopifnot(inherits(datM, "Date"), inherits(timM, "POSIXt"), |
| substring(format(datM), 9,10) == "01", # first of month |
| substring(format(datY), 6,10) == "01-01", # Jan 1 |
| identical(format(datM), format(timM)), |
| identical(format(datY), format(timY))) |
| } |
| \keyword{chron} |