Creating date/times

suppressPackageStartupMessages(library("tidyverse"))

package 㤼㸱tidyverse㤼㸲 was built under R version 3.6.3

suppressPackageStartupMessages(library("lubridate"))

1. What happens if you parse a string that contains invalid dates?

ret <- ymd(c("2010-10-10", "bananas"))

 1 failed to parse.

print(class(ret))

[1] "Date"

ret

[1] "2010-10-10" NA          

It produces an NA and a warning message.

2. What does the tzone argument to today() do? Why is it important?

It determines the time-zone of the date. Since different time-zones can have different dates, the value of today() can vary depending on the time-zone specified.

3. Use the appropriate lubridate function to parse each of the following dates:

d1 <- "January 1, 2010"
d2 <- "2015-Mar-07"
d3 <- "06-Jun-2017"
d4 <- c("August 19 (2015)", "July 1 (2015)")
d5 <- "12/30/14"

mdy(d1)

[1] "2010-01-01"

ymd(d2)

[1] "2015-03-07"

dmy(d3)

[1] "2017-06-06"

mdy(d4)

[1] "2015-08-19" "2015-07-01"

mdy(d5)

[1] "2014-12-30"