stri_datetime_add: Date and Time Arithmetic¶

Description¶

Modifies a date-time object by adding a specific amount of time units.

Usage¶

stri_datetime_add(
  time,
  value = 1L,
  units = "seconds",
  tz = NULL,
  locale = NULL
)

stri_datetime_add(time, units = "seconds", tz = NULL, locale = NULL) <- value

Arguments¶


`time`	an object of class `POSIXct` (`as.POSIXct` will be called on character vectors and objects of class `POSIXlt`, `Date`, and `factor`)
`value`	integer vector; signed number of units to add to `time`
`units`	single string; one of `'years'`, `'months'`, `'weeks'`, `'days'`, `'hours'`, `'minutes'`, `'seconds'`, or `'milliseconds'`
`tz`	`NULL` or `''` for the default time zone or a single string with a timezone identifier,
`locale`	`NULL` or `''` for default locale, or a single string with locale identifier; a non-Gregorian calendar may be specified by setting the `@calendar=name` keyword

Details¶

Vectorized over time and value.

Note that, e.g., January, 31 + 1 month = February, 28 or 29.

Value¶

Both functions return an object of class POSIXct.

The replacement version of stri_datetime_add modifies the state of the time object.

Author(s)¶

Marek Gagolewski and other contributors

References¶

Calendar Classes - ICU User Guide, https://unicode-org.github.io/icu/userguide/datetime/calendar/

Examples¶

x <- stri_datetime_now()
stri_datetime_add(x, units='months') <- 2
print(x)
## [1] "2021-11-03 10:33:16 AEDT"
stri_datetime_add(x, -2, units='months')
## [1] "2021-09-03 10:33:16 AEST"
stri_datetime_add(stri_datetime_create(2014, 4, 20), 1, units='years')
## [1] "2015-04-20 12:00:00 AEST"
stri_datetime_add(stri_datetime_create(2014, 4, 20), 1, units='years', locale='@calendar=hebrew')
## [1] "2015-04-09 12:00:00 AEST"
stri_datetime_add(stri_datetime_create(2016, 1, 31), 1, units='months')
## [1] "2016-02-29 12:00:00 AEDT"