Dates and Times

Question 1

as.Date(s) and as.POSIXct(s)

Answer 1

as.Date(s) and as.POSIXct(s) convert to the respective class; format(dt) converts to a string representation. The default string format is “2001-02-21”.

Question 2

%a, %A

Answer 2

Abbreviated and full weekday name.

Question 3

%b, %B

Answer 3

Abbreviated and full month name.

Question 4

%d

Answer 4

Day of the month (01–31).

Question 5

%H

Answer 5

Hours (00–23).

Question 6

%I

Answer 6

Hours (01–12).

Question 7

%j

Answer 7

Day of year (001–366).

Question 8

%m

Answer 8

Month (01–12).

Question 9

%M

Answer 9

Minute (00–59).

Question 10

%p

Answer 10

AM/PM indicator.

Question 11

%S

Answer 11

Second as decimal number (00–61).

Question 12

%U

Answer 12

Week (00–53); the first Sunday as day 1 of week 1.

Question 13

%w

Answer 13

Weekday (0–6, Sunday is 0).

Question 14

%W

Answer 14

Week (00–53); the first Monday as day 1 of week 1.

Question 15

%y

Answer 15

Year without century (00–99). Don’t use.

Question 16

%Y

Answer 16

Year with century.

Question 17

%z

Answer 17

(output only.) Offset from Greenwich; -0800 is 8 hours west of.

Question 18

%Z

Answer 18

(output only.) Time zone as a character string (empty if not available).