Date & Time internationalisation

N

Nick Stansbury

Hi,

I'm currently building a client/server calendar system with access as
the primary front end and sql server 2000 at the back end. I also have a
web-front end that hasn't been finished yet. I've come up against an
internationalisation issue with time's.

Users are already using the system from Scandinavia, India and the UK,
and are soon going to be using it from a number of other countries as well.
They are putting in events occuring pretty much all over the developed world
(certainly most major cities).

My issue concerns time zones - at the moment my policy decision has been
to put in all events timing's in GMT (UTC for non anglo-philes). This is
causing a number of problems for my users - most of whom get GMT wrong
pretty much all the time - they get confused with BST (British summer time)
and their own daylight savings time - and the whole thing is a mess. What
I'd like to do is two fold :

1) Build a "time picker" that works something like this - the user puts in
08:45 , picks "local time" and then selects a city. My system then converts
it to GMT and puts it into the appropriate field. The time picker should
take account of the date the event is taking place at, calculate the
difference *on that date* between the local time and GMT and make the
appropriate calculation. (So taking into account daylight savings time it
would need to adjust by 1 hour for an event taking place in London today,
but by 0 hours for an event in London next week).

2) Add a "localisation" feature to our calendar display that allows two
things - 1) Converts all times *back* into the appropriate local time and
displays them as such, 2) Converts all times to a fixed time zone - i.e.
shows all events in New York time. This also would have to check each
individual date and display them appropriately.

So...how do I do this? I don't even know where to start! I know there is
some very obscure TimeZone database here: ftp://elsie.nci.nih.gov/pub/ but
I've got no clue how to use it - other than parsing a huge number of files
in different ways. TimeAndDate.Com is building a webservice to do this sort
of thing on a one-off basis - but I reckon that a webservice would be
restrictively slow to pull data *out* because it would have to make separate
checks for each event because of daylight savings. Also - how do I join
these zones to cities? Is there a global database of cities somewhere that I
could base it on?

Any pointers anyone?

Thanks!

Nick
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top