On Fri, 23 Jul 2010, Elliot Merrony wrote:
To start from the beginning, I've been using the DT and DT:TZ modules for a
world clock and want to add a feature which displays the time, date and
effect of the next DST transition (if any) for each location.
The modules seem to allow me to do anything I could possibly imagine with
times and time zones, except this. I realise I could test whether each
location is on DST for every hour from now until 6 months ahead, but was
hoping that there was a more elegant way of determining when the transition
is.
Asking around, I was advised that the _rules attribute of an
DateTime::TimeZone object returns an array of
DateTime::TimeZone::OlsonDB::Rule objects which encode the start
and end of DST observances.
However, I'm now understanding from Dave's response to the bug that the
_rules attribute neither is nor should be used for this purpose.
Any advice welcomed. Please bear in mind I'm a Perl beginner (I'm only using
it due to the existence of these modules!) so apologies for any
misunderstanding.
Basically, I think we could have a better API than returning the raw
rules. Off the top of my head, I think a DateTime::Event module that let
you ask for the next transition in a set would work well. Of course, that
might still require opening up some chunk of the DT::TimeZone API, but I
don't want to expose the raw _rules attribute directly.
-dave
/*
http://VegGuide.org http://blog.urth.org
Your guide to all that's veg House Absolute(ly Pointless)
*/
