R Language lubridate Intervals, Durations and Periods
Example
Intervals are simplest way of recording timespans in lubridate. An interval is a span of time that occurs between two specific instants.
# create interval by substracting two instants
today_start <- ymd_hms("2016-07-22 12-00-00", tz="IST")
today_start
## [1] "2016-07-22 12:00:00 IST"
today_end <- ymd_hms("2016-07-22 23-59-59", tz="IST")
today_end
## [1] "2016-07-22 23:59:59 IST"
span <- today_end - today_start
span
## Time difference of 11.99972 hours
as.interval(span, today_start)
## [1] 2016-07-22 12:00:00 IST--2016-07-22 23:59:59 IST
# create interval using interval() function
span <- interval(today_start, today_end)
[1] 2016-07-22 12:00:00 IST--2016-07-22 23:59:59 IST
Durations measure the exact amount of time that occurs between two instants.
duration(60, "seconds")
## [1] "60s"
duration(2, "minutes")
## [1] "120s (~2 minutes)"
Note: Units larger than weeks are not used due to their variability.
Durations can be created using dseconds, dminutes and other duration helper functions.
Run ?quick_durations for complete list.
dseconds(60)
## [1] "60s"
dhours(2)
## [1] "7200s (~2 hours)"
dyears(1)
## [1] "31536000s (~365 days)"
Durations can be subtracted and added to instants to get new instants.
today_start + dhours(5)
## [1] "2016-07-22 17:00:00 IST"
today_start + dhours(5) + dminutes(30) + dseconds(15)
## [1] "2016-07-22 17:30:15 IST"
Durations can be created from intervals.
as.duration(span)
[1] "43199s (~12 hours)"
Periods measure the change in clock time that occurs between two instants.
Periods can be created using period function as well other helper functions
like seconds, hours, etc. To get a complete list of period helper functions, Run ?quick_periods.
period(1, "hour")
## [1] "1H 0M 0S"
hours(1)
## [1] "1H 0M 0S"
period(6, "months")
## [1] "6m 0d 0H 0M 0S"
months(6)
## [1] "6m 0d 0H 0M 0S"
years(1)
## [1] "1y 0m 0d 0H 0M 0S"
is.period function can be used to check if an object is a period.
is.period(years(1))
## [1] TRUE
is.period(dyears(1))
## [1] FALSE
