trunc.POSIXt {Hmisc} | R Documentation

## return the floor, ceiling, or rounded value of date or time to specified unit.

### Description

`trunc.POSIXt` returns the date truncated to the specified unit. `ceiling.POSIXt` returns next ceiling of the date at the unit selected in `units`. `floor.POSIXt` `trunk.POSIXt` by another name. `round.POSIXt` returns the date or time value rounded to nearest specified unit selected in `digits`.

`trunc.POSIXt` and `round.POSIXt` have been extended from the `base` package functions.

### Usage

    ceil(x, units,...)
    ## Default S3 method:
    ceil(x, units, ...)
    ## S3 method for class 'POSIXt'
    trunc(x, units = c("secs", "mins", "hours", "days",
    "months", "years"), ...)
    ## S3 method for class 'POSIXt'
    ceil(x, units = c("secs", "mins", "hours", "days",
    "months", "years"), ...)
    ## S3 method for class 'POSIXt'
    round(x, digits = c("secs", "mins", "hours", "days", "months", "years"))

### Arguments

`x` | date to be floored, ceilinged, truncated, or rounded
`units` | unit to that is is rounded up or down to.
`digits` | same as `units` but different name to be compatible with `round` generic.
`...` | further arguments to be passed to or from other methods.

### Value

An object of class `POSIXlt`.

### Author(s)

Charles Dupont

### See Also

`Date` `POSIXt` `POSIXlt` `DateTimeClasses`

### Examples

    date <- ISOdate(1832, 7, 12)
    ceil(date, units='months')  # '1832-8-1'
    trunc(date, units='years')     # '1832-1-1'
    round.POSIXt(date, digits='months')    # '1832-7-1'

[Package Hmisc version 3.17-4 Index]