@defvr {Optional} @code{creation-date-time}
The date and time at which the SPV file was written, in a
-locale-specific format, e.g. @code{Friday, May 16, 2014 6:47:37 PM
+locale-specific format, e.g.@: @code{Friday, May 16, 2014 6:47:37 PM
PDT} or @code{lunedì 17 marzo 2014 3.15.48 CET} or even @code{Friday,
December 5, 2014 5:00:19 o'clock PM EST}.
@end defvr