Class `POSIXlt` more conveniently represents the result of Class `POSIXct` (the number of seconds since the beginning of 1970) as a numeric vector of more directly accessable values for seconds, minutes, hours, days, months, years etc.
Class POSIXct represents the (signed) number of seconds since the beginning of 1970 (in the UTC time zone) as a numeric vector. Class "POSIXlt" is a named list of vectors representing
sec - 0–61: seconds.
min - 0–59: minutes.
hour - 0–23: hours.
mday - 1–31: day of the month
mon - 0–11: months after the first of the year.
year - years since 1900.
wday - 0–6 day of the week, starting on Sunday.
yday - 0–365: day of the year.
isdst - Daylight Saving Time flag. Positive if in force, zero if not, negative if unknown.
zone - (Optional.) The abbreviation for the time zone in force at that time: "" if unknown (but "" might also be used for UTC).
gmtoff - (Optional.) The offset in seconds from GMT: positive values are East of the meridian. Usually NA if unknown, but 0 could mean unknown.
