a chron object, a character vector, or a numeric vector
specifying time. If character, it must be in a format recognized by
chron(). If numeric, it specifies Julian dates, i.e., number
of days since an origin.
...
parameters for chron().
Value
An object of class dates or times, depending of the
function called.
These functions return objects inheriting from dates and times,
respectively. They call chron() if x does not belong to
any of the chronological classes.