Fit a POSIXlt date-time to the timeline
The POSIXlt format allows you to create instants that do not exist in real life due to daylight savings time and other conventions. fit_to_timeline matches POSIXlt date-times to a real times. If an instant does not exist, fit to timeline will replace it with an NA. If an instant does exist, but has been paired with an incorrect timezone/daylight savings time combination, fit_to_timeline returns the instant with the correct combination.
fit_to_timeline(lt, class = "POSIXct", simple = FALSE)
lt |
a POSIXlt date-time object. |
class |
a character string that describes what type of object to return, POSIXlt or POSIXct. Defaults to POSIXct. This is an optimization to avoid needless conversions. |
simple |
if TRUE, lubridate makes no attempt to detect meaningless time-dates or to correct time zones. No NAs are produced and the most meaningful valid dates are returned instead. See examples. |
a POSIXct or POSIXlt object that contains no illusory date-times
## Not run:
tricky <- structure(list(sec = c(5, 0, 0, -1),
min = c(0L, 5L, 5L, 0L),
hour = c(2L, 0L, 2L, 2L),
mday = c(4L, 4L, 14L, 4L),
mon = c(10L, 10L, 2L, 10L),
year = c(112L, 112L, 110L, 112L),
wday = c(0L, 0L, 0L, 0L),
yday = c(308L, 308L, 72L, 308L),
isdst = c(1L, 0L, 0L, 1L)),
.Names = c("sec", "min", "hour", "mday", "mon",
"year", "wday", "yday", "isdst"),
class = c("POSIXlt", "POSIXt"),
tzone = c("America/Chicago", "CST", "CDT"))
tricky
## [1] "2012-11-04 02:00:00 CDT" Doesn't exist because clocks "fall back" to 1:00 CST
## [2] "2012-11-04 00:05:00 CST" Times are still CDT, not CST at this instant
## [3] "2010-03-14 02:00:00 CDT" DST gap
## [4] "2012-11-04 01:59:59 CDT" Does exist, but has deceptive internal structure
fit_to_timeline(tricky)
## Returns:
## [1] "2012-11-04 02:00:00 CST" instant paired with correct tz & DST combination
## [2] "2012-11-04 00:05:00 CDT" instant paired with correct tz & DST combination
## [3] NA - fake time changed to NA (compare to as.POSIXct(tricky))
## [4] "2012-11-04 01:59:59 CDT" -real instant, left as is
fit_to_timeline(tricky, simple = TRUE)
## Returns valid time-dates by extrapolating CDT and CST zones:
## [1] "2012-11-04 01:00:05 CST" "2012-11-04 01:05:00 CDT"
## [3] "2010-03-14 03:05:00 CDT" "2012-11-04 01:59:59 CDT"
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.