Change an object to a period.
as.period changes Interval, Duration, difftime and numeric class objects to Period class objects with the specified units.
as.period(x, unit, ...)
- an interval, difftime, or numeric object
- A character string that specifies which time units to build period in. unit is only implemented for the as.period.numeric method.
- additional arguments to pass to as.period
Users must specify which time units to measure the period
in. The exact length of each time unit in a period will
depend on when it occurs. See
new_period. The choice of units is not
trivial; units that are normally equal may differ in
length depending on when the time period occurs. For
example, when a leap second occurs one minute is longer
than 60 seconds.
Because periods do not have a fixed length, they can not
be accurately converted to and from Duration objects.
Duration objects measure time spans in exact numbers of
Duration-class. Hence, a one
to one mapping does not exist between durations and
periods. When used with a Duration object, as.period
provides an inexact estimate; the duration is broken into
time units based on the most common lengths of time
units, in seconds. Because the length of months are
particularly variable, a period with a months unit can
not be coerced from a duration object. For an exact
transformation, first transform the duration to an
- a period object
span <- new_interval(as.POSIXct("2009-01-01"), as.POSIXct("2010-02-02 01:01:01")) #interval # 2009-01-01 CST--2010-02-02 01:01:01 CST as.period(span) # 1 year, 1 month, 1 day, 1 hour, 1 minute and 1 second