This module's default exports override the core gmtime() function,
replacing it with a version that returns ``Time::tm'' objects.
This object has methods that return the similarly named structure field
name from the C's tm structure from time.h; namely sec, min, hour,
mday, mon, year, wday, yday, and isdst.
You may also import all the structure fields directly into your namespace
as regular variables using the :FIELDS import tag. (Note that this
still overrides your core functions.) Access these fields as variables
named with a preceding tm_ in front their method names. Thus,
$tm_obj->mday() corresponds to $tm_mday if you import the fields.
The gmctime() function provides a way of getting at the
scalar sense of the original CORE::gmtime() function.
To access this functionality without the core overrides,
pass the use an empty import list, and then access
function functions with their full qualified names.
On the other hand, the built-ins are still available
via the CORE:: pseudo-package.