Tim Prince <[log in to unmask]> wrote:
> My understanding of DATE_AND_TIME, reinforced by the way it was implemented by CVF, MipsPro, and Lahey, and by the absence of bug reports on our g77 library version, is that the TIME field returns local time, and the ZONE field reflects the difference between that time and UTC. Other vendors read Adams, Brainerd et al "Fortran 95 Handbook" and come up with a different result, even though inter-operability with CVF and SGI compilers has been given as a stated goal. Is this a point where the standard allows variation?
The standard is silent concerning which time zone the DATE_AND_TIME
subroutine is required to use to compute its outputs. It is my opinion
(and this is only an opinion) that the processor can return anything
it wishes in DATE, TIME and VALUES, so long as combining them with ZONE
or VALUES(4) gives UTC. So the difference between the reported date/time
and UTC could be +/- 99 hours and 99 minutes if the ZONE argument is
present, +/- HUGE(0) minutes if ZONE is absent and VALUES is present,
and anything at all otherwise. Particularly interesting values are local
time (different from UTC by less than +/- 24 hours), or UTC (with ZONE ==
"+0000" (or "-0000") and VALUES(4) == 0).
--
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Any alleged opinions are my own and have not been approved or disapproved
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