5.6 R 날짜와 시간 함수

seq() difftime() as.Date(s) and as.POSIXct(s) format(dt)

%a, %A Abbreviated and full weekday name. %b, %B Abbreviated and full month name. %d Day of the month (01–31). %H Hours (00–23). %I Hours (01–12). %j Day of year (001–366). %m Month (01–12). %M Minute (00–59). %p AM/PM indicator. %S Second as decimal number (00–61). %U Week (00–53); the first Sunday as day 1 of week 1. %w Weekday (0–6, Sunday is 0). %W Week (00–53); the first Monday as day 1 of week 1. %y Year without century (00–99). Don’t use. %Y Year with century. %z (output only.) Offset from Greenwich; -0800 is 8 hours west of. %Z (output only.) Time zone as a character string (empty if not available).