当前日期和时间
R 能够访问当前日期,时间和时区:
Sys.Date() # Returns date as a Date object
## [1] "2016-07-21"
Sys.time() # Returns date & time at current locale as a POSIXct object
## [1] "2016-07-21 10:04:39 CDT"
as.numeric(Sys.time()) # Seconds from UNIX Epoch (1970-01-01 00:00:00 UTC)
## [1] 1469113479
Sys.timezone() # Time zone at current location
## [1] "Australia/Melbourne"
使用 OlsonNames()
查看当前系统上 Olson / IANA 数据库中的时区名称:
str(OlsonNames())
## chr [1:589] "Africa/Abidjan" "Africa/Accra" "Africa/Addis_Ababa" "Africa/Algiers" "Africa/Asmara" "Africa/Asmera" "Africa/Bamako" ...