Tutorials on the lubridate Package

The objective of this tutorial is to explore several functions of the lubridate package to manipulate time and date objects.

 df <- data.frame(Date = c("10/9/2009 0:00:00", "10/15/2009 0:00:00"))
 as.Date(df$Date, "%m/%d/%Y %H:%M:%S")

[1] "2009-10-09" "2009-10-15"

mytime<-ymd_hms("2015-08-14-05-30-00", tz="America/Halifax")
mytime

[1] "2015-08-14 05:30:00 ADT"

date(mytime)

[1] "2015-08-14"

Check for Leap Years in date

leap_year(mytime)

[1] FALSE

Check for Time Intervals

date1<-ymd_hms("2017-06-20-03-45-23")
date2<-ymd_hms("2017-10-07-21-02-19")
difftime(date2,date1)

Time difference of 109.7201 days

get current date or time

lubridate::today()  

[1] "2017-08-28"

base::date()

[1] "Mon Aug 28 20:24:47 2017"

Sys.Date()

[1] "2017-08-28"

Sys.timezone()

[1] "America/Detroit"

now()

[1] "2017-08-28 20:24:47 EDT"

Extract day,month,year from date

year=year(today())
month=month(today())
day=day(today())
cbind.data.frame(year,month,day)

week <- wday(today())
month <- mday(today())
year <- yday(today())
cbind.data.frame(week,month,year)

week <- wday(today(),label=TRUE,abbr = FALSE)
#month <- mday(today(),label=TRUE,abbr = TRUE)
#year <- yday(today(),label=TRUE,abbr = TRUE)
cbind.data.frame(week,month,year)

formatting time

ymd(date(mytime))

[1] "2015-08-14"

ymd_hms(mytime)

[1] "2015-08-14 05:30:00 UTC"

mdy("March 6, 1957")

[1] "1957-03-06"

dmy("03/06/2015")

[1] "2015-06-03"

dmy(16082015)

[1] "2015-08-16"

ymd("1988/21/2")

All formats failed to parse. No formats found.

[1] NA

Parsing date-times

ymd_hms('2009-08-23 17:20:02')

[1] "2009-08-23 17:20:02 UTC"

hms("09:12:15")

[1] "9H 12M 15S"

hms(c('2014-05-14', '2014-09-22', '2014-07-11'))

[1] "2014H -5M -14S" "2014H -9M -22S" "2014H -7M -11S"

ymd_hms("2011-06-04 12:00:00", tz = "")

[1] "2011-06-04 12:00:00 EDT"

date <- as.POSIXct("01-01-2010", 
format = "%d-%m-%Y", tz = "UTC")
date <- dmy("01-01-2010")

date time occur in the am or pm

 x <- ymd("2012-03-26")
    am(x)

[1] TRUE

    pm(x)

[1] FALSE

mytime    

[1] "2015-08-14 05:30:00 ADT"

am(mytime)    

[1] TRUE

Change an object to an interval.

diff <- make_difftime(days = 31) #difftime
diff

Time difference of 31 days

as.interval(diff, ymd("2009-01-01"))

[1] 2009-01-01 UTC--2009-02-01 UTC

as.interval(diff, ymd("2009-02-01"))

[1] 2009-02-01 UTC--2009-03-04 UTC

Change an object to a duration.

x <- interval(ymd("2017-01-01"), ymd("2009-08-01")) #interval
x  

[1] 2017-01-01 UTC--2009-08-01 UTC

as.duration(x)

[1] "234144000s (~7.42 years)"

 
as.duration(10) # numeric

[1] "10s"

dur <- duration(hours = 10, minutes = 6)
as.numeric(dur, "hours")

[1] 10.1

as.numeric(dur, "minutes")   

[1] 606

Change an object to a period.

x <- interval(as.POSIXct("2009-01-01"), as.POSIXct("2010-02-02 01:01:01")) #interval
as.period(x)

[1] "1y 1m 1d 1H 1M 1S"

as.period(x, units = "day")

[1] "1y 1m 1d 1H 1M 1S"

leap <- interval(ymd("2016-01-01"), ymd("2017-01-01"))
    as.period(leap, unit = "days")

[1] "366d 0H 0M 0S"

    as.period(leap, unit = "years")

[1] "1y 0m 0d 0H 0M 0S"

    dst <- interval(ymd("2016-11-06", tz = "America/Chicago"),
    ymd("2016-11-07", tz = "America/Chicago"))
    # as.period(dst, unit = "seconds")
    as.period(dst, unit = "hours")

[1] "25H 0M 0S"

    per <- period(hours = 10, minutes = 6)
    as.numeric(per, "hours")

[1] 10.1

    as.numeric(per, "minutes")

[1] 606

Convert an object to a date or date-time

## S4 method for signature 'numeric'
    as_datetime(x, origin = lubridate::origin, tz = "UTC")

a vector of Date objects corresponding to x.

dt_utc <- ymd_hms("2010-08-03 00:50:50")
    dt_europe <- ymd_hms("2010-08-03 00:50:50", tz="Europe/London")
    c(as_date(dt_utc), as.Date(dt_utc))
    c(as_date(dt_europe), as.Date(dt_europe))