Intervals
Working with Dates and Times in R
Charlotte Wickham
Instructor
Creating intervals
datetime1 %--% datetime2, orinterval(datetime1, datetime2)
dmy("5 January 1961") %--% dmy("30 January 1969")
1961-01-05 UTC--1969-01-30 UTC
interval(dmy("5 January 1961"), dmy("30 January 1969"))
1961-01-05 UTC--1969-01-30 UTC
Operating on an interval
beatles <- dmy("5 January 1961") %--% dmy("30 January 1969")int_start(beatles)
"1961-01-05 UTC"
int_end(beatles)
"1969-01-30 UTC"
Operating on an interval
int_length(beatles)
254620800
as.period(beatles)
"8y 0m 25d 0H 0M 0S"
as.duration(beatles)
"254620800s (~8.07 years)"
Comparing intervals
hendrix_at_woodstock <- mdy("August 17 1969")
hendrix_at_woodstock %within% beatles
FALSE
hendrix <- dmy("01 October 1966") %--% dmy("16 September 1970")
int_overlaps(beatles, hendrix)
TRUE
Which kind of time span?
Use:
- Intervals when you have a start and end
- Periods when you are interested in human units
- Durations if you are interested in seconds elapsed
Monarchs of England
monarchs
# A tibble: 131 x 4
name from to dominion
<chr> <dttm> <dttm> <chr>
1 Elizabeth II 1952-02-06 2017-10-07 United Kingdom
2 Victoria 1837-06-20 1901-01-22 United Kingdom
3 George V 1910-05-06 1936-01-20 United Kingdom
4 George III 1801-01-01 1820-01-29 United Kingdom
# ... with 127 more rows
Halley's comet
Halley's comet: https://en.wikipedia.org/wiki/Halley%27s_Comet#Apparitions
halleys
# A tibble: 27 x 6
designation year perihelion_date start_date end_date distance
<chr> <int> <date> <date> <date> <chr>
1 1P/66 B1, 66 66 0066-01-26 0066-01-25 0066-01-26 <NA>
2 1P/141 F1, 141 141 0141-03-25 0141-03-22 0141-03-25 <NA>
3 1P/218 H1, 218 218 0218-04-06 0218-04-06 0218-05-17 <NA>
4 1P/295 J1, 295 295 0295-04-07 0295-04-07 0295-04-20 <NA>
# ... with 23 more rows
Let's practice!
Working with Dates and Times in R
