Taking differences of datetimes

Working with Dates and Times in R

Charlotte Wickham

Instructor

Arithmetic for datetimes

datetime_1 - datetime2: Subtraction for time elapsed
datetime_1 + (2 * timespan): Addition and multiplication for generating new datetimes in the past or future
timespan1 / timespan2: Division for change of units

releases <- read_csv("rversions.csv")
last_release <- filter(releases, date == max(date))

Sys.Date() - last_release$date

Time difference of 99 days

difftime(Sys.Date(), last_release$date)

Time difference of 99 days

time1 - time2 is the same as difftime(time1, time2)

units = "secs", "mins", "hours", "days", or "weeks"

difftime(Sys.Date(), last_release$date, units = "secs")

Time difference of 8553600 secs

difftime(Sys.Date(), last_release$date, units = "weeks")

Time difference of 14.14286 weeks

today()

"2017-10-07"

str(today())

 Date[1:1], format: "2017-10-07"

now()

"2017-10-07 09:44:52 PDT"

str(now())

 POSIXct[1:1], format: "2017-10-07 09:44:59"

Working with Dates and Times in R