as.interval: Change an object to an interval.

Description

Change an object to an interval.

Usage

as.interval(x, start)

Arguments

a duration (i.e. difftime), period, or numeric object that describes the length of the interval

start

a POSIXt or Date object that describes when the interval begins

Value

an interval object

Details

as.interval changes difftime, duration, period and numeric objects to intervals that begin at the specified date-time. Numeric objects are first coerced to time spans equal to the numeric value in seconds.

as.interval can be used to create accurate transformations between period objects, which measure time spans in variable length units, and difftime objects, which measure timespans as an exact number of seconds. A start date- time must be supplied to make the conversion. Lubridate uses this start date to look up how many seconds each variable length unit (e.g. month, year) lasted for during the time span described. See as.duration, as.period.

Examples

Run this code

diff <- new_difftime(days = 31) #difftime
as.interval(diff, ymd("2009-01-01"))
# 2009-01-01 -- 2009-02-01
as.interval(diff, ymd("2009-02-01"))
# 2009-02-01 -- 2009-03-04

dur <- new_duration(days = 31) #duration
as.interval(dur, ymd("2009-01-01"))
# 2009-01-01 -- 2009-02-01
as.interval(dur, ymd("2009-02-01"))
# 2009-02-01 -- 2009-03-04

per <- new_period(months = 1) #period
as.interval(per, ymd("2009-01-01"))
# 2009-01-01 -- 2009-02-01 
as.interval(per, ymd("2009-02-01"))
# 2009-02-01 -- 2009-03-01

as.interval(3600, ymd("2009-01-01")) #numeric
# 2009-01-01 -- 2009-01-01 01:00:00}