difftime {base} | R Documentation |

## Time Intervals

### Description

Create, print and round time intervals.

### Usage

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)

### Arguments

`time1, time2` |
date-time 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` . |

`x` |
an object inheriting from class `"difftime"` . |

`digits` |
integer. Number of significant digits to retain. |

### Details

Function `difftime`

takes a difference of two date/time objects
(of either class) 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 two 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.

### See Also

`DateTimeClasses`

.

### Examples

(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

[Package

*base* version 2.2.1

Index]