some large number. C<$offset> can then be added to a Unix time value
to get what should be the proper value on any system.
-On Windows (at least), you shouldn't pass a negative value to C<gmtime> or
-C<localtime>.
-
=head2 Character sets and character encoding
Assume very little about character sets.
C<-b>, C<-c>, C<-k>, C<-g>, C<-p>, C<-u>, C<-A> are not implemented.
(S<Mac OS>)
-C<-g>, C<-k>, C<-l>, C<-p>, C<-u>, C<-A> are not particularly meaningful.
+C<-g>, C<-k>, C<-l>, C<-u>, C<-A> are not particularly meaningful.
(Win32, VMS, S<RISC OS>)
+C<-p> is not particularly meaningful. (VMS, S<RISC OS>)
+
C<-d> is true if passed a device spec without an explicit directory.
(VMS)
=item gmtime
-Same portability caveats as L<localtime>.
+In theory, gmtime() is reliable from -2**63 to 2**63-1. However,
+because work arounds in the implementation use floating point numbers,
+it will become inaccurate as the time gets larger. This is a bug and
+will be fixed in the future.
=item ioctl FILEHANDLE,FUNCTION,SCALAR
=item localtime
-Because Perl currently relies on the native standard C localtime()
-function, it is only safe to use times between 0 and (2**31)-1. Times
-outside this range may result in unexpected behavior depending on your
-operating system's implementation of localtime().
+localtime() has the same range as L<gmtime>, but because time zone
+rules change its accuracy for historical and future times may degrade
+but usually by no more than an hour.
=item lstat