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DateTime Axes

Posted: Thu Aug 03, 2006 3:07 pm
by 9790735
Hi,

when setting the Y-axis to DateTime, does it expect the values to be UTC or LOCALTIME? How does the axis look when it spans the STD/DST time change.

thanks,

Brian

Posted: Fri Aug 04, 2006 11:24 am
by Pep
Hi Brian,

please take a look at the TeeChart for Net Tutorial 6 and Tutorial 4 which shows how to use DateTime values for Series and on the Axis.

Posted: Fri Aug 04, 2006 12:59 pm
by 9790735
I took a look, but nowhere does it mention UTC or STD/DST

Brian

Posted: Mon Aug 07, 2006 11:58 am
by Chris
Hello Brian,

Are you working with a Web application or a Win application? From what you've said it sounds as though you're trying to get your charts generated on a server and then have them appear with local datetimes depending on the time zone of the browser that's viewing the app. Is this correct? Could you please be a little more specific as to what you would like to achieve?

Posted: Tue Aug 08, 2006 4:40 pm
by 9790735
We are working with a Win application. There is a client-server relationship, but I am actually concerned with the display when both client and server are in the same timezone.

For example, when the Daylight savings switches back one hour in October for the Pacific Standard Timezone, the clock goes 12:00 - 1:00 - 1:00 2:00. So we get data with the same localtime for 2 hours. That is, 1:00 to 2:00 repeats after the clock gets switched back.

The UTC time of course does not repeat. My question is then, how is this displayed on the Y-Axis of a DateTime Graph? Do you see the local times, and therefore the repeated hour?

I will test anyway.

thanks,

Posted: Tue Aug 08, 2006 4:52 pm
by 9790735
In fact I have just tested it. I set the starttime to 29-Oct-2005 06:00 and the endtime to 30-Oct-2005 06:00. The datetime axis does not show the extra hour at DST-STD switch time of 02:00. 30-Oct is not showing 25-Hours

This is quite important to us. Is there anyway to change this? That is, use UTC datetime stamps and make the axis display localtime?

I just could not find any mention of this in the documentation.

thanks,

Posted: Tue Aug 08, 2006 5:27 pm
by Chris
Hello Brian,

This thread is almost identical with this one:

http://www.teechart.net/support/viewtopic.php?t=4561

Here I mentioned a demo in the features demo that you might like to study. I think it should solve your problem.