Create a POSIXct Object

Easily create of time stamps corresponding to the first or last observation in a specified time period.

firstof(year = 1970, month = 1, day = 1, hour = 0, min = 0, sec = 0, tz = "")

lastof(
  year = 1970,
  month = 12,
  day = 31,
  hour = 23,
  min = 59,
  sec = 59,
  subsec = 0.99999,
  tz = ""
)

Arguments

year, month, day

Numeric values to specify a day.

hour, min, sec

Numeric vaues to specify time within a day.

tz

Timezone used for conversion.

subsec

Number of sub-seconds.

Value

An POSIXct object.

Details

This is a wrapper to ISOdatetime() with defaults corresponding to the first or last possible time in a given period.

See also

ISOdatetime()

Author

Jeffrey A. Ryan

Examples

firstof(2000)
#> [1] "2000-01-01 UTC"
firstof(2005,01,01)
#> [1] "2005-01-01 UTC"

lastof(2007)
#> [1] "2007-12-31 23:59:59 UTC"
lastof(2007,10)
#> [1] "2007-10-31 23:59:59 UTC"