| difftime {base} | R Documentation |
Create, print and round time intervals.
time1 - time2
difftime(time1, time2, tz = "",
units = c("auto", "secs", "mins", "hours", "days", "weeks"))
as.difftime(tim, format = "%X")
## S3 method for class 'difftime':
round(x, digits = 0)
time1, time2 |
date-time or date objects. |
tz |
a timezone specification to be used for the conversion.
System-specific, but "" is the current time zone, and
"GMT" is UTC. |
units |
character. Units in which the results are desired. Can be abbreviated. |
tim |
character string specifying a time interval. |
format |
character specifying the format of tim: see
strptime. The default is a locale-specific time format. |
x |
an object inheriting from class "difftime". |
digits |
integer. Number of significant digits to retain. |
Function difftime takes a difference of two date/time objects
and returns an object of class "difftime"
with an attribute indicating the units. There is a round
method for objects of this class, as well as methods for the
group-generic (see Ops) logical and
arithmetic operations.
If units = "auto", a suitable set of units is chosen, the largest
possible (excluding "weeks") in which all the absolute
differences are greater than one.
Subtraction of date-time objects gives an object of this class,
by calling difftime with units="auto". Alternatively,
as.difftime() works on character-coded time intervals.
Limited arithmetic is available on "difftime" objects: they can
be added or subtracted, and multiplied or divided by a numeric vector.
In addition, adding or subtracting a numeric vector implicitly
converts the numeric vector to a "difftime" object with the
same units as the "difftime" object.
(z <- Sys.time() - 3600)
Sys.time() - z # just over 3600 seconds.
## time interval between releases of 1.2.2 and 1.2.3.
ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26)
as.difftime(c("0:3:20", "11:23:15"))
as.difftime(c("3:20", "23:15", "2:"), format= "%H:%M")# 3rd gives NA