seconds

Quickly create relative timespans.

Quickly create Period objects for easy date-time manipulation. The units of the period created depend on the name of the function called. For Period objects, units do not have a fixed length until they are added to a specific date time, contrast this with new_duration. This makes periods useful for manipulations with clock times because units expand or contract in length to accomodate conventions such as leap years, leap seconds, and Daylight Savings Time.

Usage

seconds(x = 1)

Details

When paired with date-times, these functions allow date-times to be manipulated in a method similar to object oriented programming. Period objects can be added to Date, POSIXct, and POSIXlt objects to calculate new date-times.

See Also

Period-class, new_period, ddays

Aliases

• days
• hours
• microseconds
• milliseconds
• minutes
• nanoseconds
• picoseconds
• seconds
• weeks
• years

Examples

x <- as.POSIXct("2009-08-03")
# "2009-08-03 CDT"
x + days(1) + hours(6) + minutes(30)
# "2009-08-04 06:30:00 CDT"
x + days(100) - hours(8)
# "2009-11-10 15:00:00 CST"

class(as.Date("2009-08-09") + days(1)) # retains Date class
# "Date"
as.Date("2009-08-09") + hours(12)
# "2009-08-09 12:00:00 UTC"
class(as.Date("2009-08-09") + hours(12))
# "POSIXt"  "POSIXct"
# converts to POSIXt class to accomodate time units

years(1) - months(7)
# "1y -7m 0d 0H 0M 0S"
c(1:3) * hours(1)
# "1H 0M 0S" "2H 0M 0S" "3H 0M 0S"
hours(1:3)
# "1H 0M 0S" "2H 0M 0S" "3H 0M 0S"

#sequencing
y <- ymd(090101) # "2009-01-01 CST"
y + months(0:11)
# [1] "2009-01-01 CST" "2009-02-01 CST" "2009-03-01 CST" "2009-04-01 CDT"
# [5] "2009-05-01 CDT" "2009-06-01 CDT" "2009-07-01 CDT" "2009-08-01 CDT"
# [9] "2009-09-01 CDT" "2009-10-01 CDT" "2009-11-01 CDT" "2009-12-01 CST"

# compare DST handling to durations
boundary <- as.POSIXct("2009-03-08 01:59:59")
# "2009-03-08 01:59:59 CST"
boundary + days(1) # period
# "2009-03-09 01:59:59 CDT" (clock time advances by a day)
boundary + edays(1) # duration
# "2009-03-09 02:59:59 CDT" (clock time corresponding to 86400 seconds later)