as.Date(x, ...) ## Default S3 method: as.Date(x, ...) ## S3 method for class 'numeric': as.Date(x, origin, ...) ## S3 method for class 'character': as.Date(x, format = "", ...) ## S3 method for class 'factor': as.Date(x, ...) ## S3 method for class 'POSIXct': as.Date(x, tz = "UTC", ...) ## S3 method for class 'POSIXlt': as.Date(x, ...) ## S3 method for class 'date': as.Date(x, ...) ## S3 method for class 'dates': as.Date(x, ...)as.POSIXct(x, tz = "", ...) ## Default S3 method: as.POSIXct(x, tz = "", ...) ## S3 method for class 'numeric': as.POSIXct(x, tz = "", origin, ...) ## S3 method for class 'Date': as.POSIXct(x, ...) ## S3 method for class 'factor': as.POSIXct(x, ...) ## S3 method for class 'POSIXlt': as.POSIXct(x, tz = "", ...) ## S3 method for class 'date': as.POSIXct(x, ...) ## S3 method for class 'dates': as.POSIXct(x, ...)
as.POSIXlt(x, tz = "", ...) ## Default S3 method: as.POSIXlt(x, tz = "", ...) ## S3 method for class 'numeric': as.POSIXlt(x, tz = "", origin, ...) ## S3 method for class 'character': as.POSIXlt(x, tz = "", format, ...) ## S3 method for class 'factor': as.POSIXlt(x, ...) ## S3 method for class 'Date': as.POSIXlt(x, ...) ## S3 method for class 'POSIXct': as.POSIXlt(x, tz = "", ...) ## S3 method for class 'date': as.POSIXlt(x, ...) ## S3 method for class 'dates': as.POSIXlt(x, ...)
strptime(x, format, tz = "")
as.difftime(tim, format = "%X", units = "auto")
x | any object to be converted to date-time. |
format |
a character string specifying the date-time format; for example, "%Y-%m-%d" "%Y-%m-%d %H:%M" "%Y-%m-%d %H:%M:%S" "%Y-%m-%d %H:%M:%OS" "%Y-%m-%d %H:%M:%OS3" |
tz | a character string specifying the time zone. |
origin | a character string specifying the starting date-time. Must be provided for the numeric methods. |
tim | any object to be converted to difftime. Usually character or numeric. |
units | a character string specifying the time unit from "auto", "secs", "mins", "hours", "days", and "weeks". |
... | additional arguments. |
as.Date.* | return a Date object representing the date. |
as.POSIXct.* | return a POSIXct object representing the date-time. |
as.POSIXlt.* | return a POSIXlt object representing the date-time. |
strptime | return a POSIXlt object representing the date-time. |
as.difftime | returns a difftime object representing the time interval. |
## convert to Date as.Date(c("1900.01.01", "1970-01-01 00:00:00", "2038/01/19 03:14:08")) as.Date("01/19/2038 03:14:08", format = "%m/%d/%Y %H:%M:%S")as.Date(-1:1, origin = "1970-01-01") as.Date(-1:1, origin = "1970-01-01 00:00:00")
as.Date(Sys.time()) as.Date(Sys.time(), tz = "Asia/Shanghai")
## convert to POSIXct as.POSIXct(c("1900.01.01", "1970-01-01 00:00:00", "2038/01/19 03:14:08")) as.POSIXct("01/19/2038 03:14:08", format = "%m/%d/%Y %H:%M:%S", tz = "Asia/Shanghai")
as.POSIXct(-1:1, origin = "1970-01-01") as.POSIXct(-1:1, origin = "1970-01-01 00:00:00", tz = "Asia/Shanghai")
as.POSIXct(Sys.Date())
## convert to POSIXlt as.POSIXlt(c("1900.01.01", "1970-01-01 00:00:00", "2038/01/19 03:14:08")) as.POSIXlt("01/19/2038 03:14:08", format = "%m/%d/%Y %H:%M:%S", tz = "Asia/Shanghai")
as.POSIXlt(-1:1, origin = "1970-01-01") as.POSIXlt(-1:1, origin = "1970-01-01 00:00:00", tz = "Asia/Shanghai") as.POSIXlt(-1:1, origin = "1970-01-01 00:00:00", tz = "GMT")
as.POSIXlt(Sys.time()) as.POSIXlt(Sys.time(), tz = "Asia/Shanghai") as.POSIXlt(Sys.time(), tz = "GMT")
as.POSIXlt(Sys.Date())
## convert to POSIXlt with strptime strptime(c("1900.01.01", "1970-01-01 00:00:00", "2038/01/19 03:14:08"), format = "") strptime("01/19/2038 03:14:08", format = "%m/%d/%Y %H:%M:%S", tz = "Asia/Shanghai")
strptime(Sys.time(), format = "") strptime(Sys.time(), format = "%Y-%m-%d %H:%M:%S") strptime(Sys.Date(), format = "")
## parse strings and numerics into difftime objects as.difftime("0:1:0", format = "%H:%M:%S", units = "secs") as.difftime("1", format = "%M", units = "secs") as.difftime(1, units = "secs")