Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.math.mathematica

Topic: Daylight savings time in DatePlus.
Replies: 4   Last Post: Jan 23, 2012 2:58 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
hmichel@cox.net

Posts: 120
Registered: 1/29/05
Re: Daylight savings time in DatePlus.
Posted: Jan 21, 2012 5:22 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Craig:

Working with just your example, using time zones

Map[Function[
DateString[ #1, If[Last[#1] < 2, TimeZone -> -6, TimeZone -> -5]]],
Map[Function[DatePlus[{2010, 1, 1, 1}, {#1, "Hour"}]],
Range[1728, 1738]]]

{Sun 14 Mar 2010 01:00:00,Sun 14 Mar 2010 03:00:00,Sun 14 Mar 2010
04:00:00,Sun 14 Mar 2010 05:00:00,Sun 14 Mar 2010 06:00:00,Sun 14 Mar 2010
07:00:00,Sun 14 Mar 2010 08:00:00,Sun 14 Mar 2010 09:00:00,Sun 14 Mar 2010
10:00:00,Sun 14 Mar 2010 11:00:00,Sun 14 Mar 2010 12:00:00}

Hans

-----Original Message-----
From: W Craig Carter [mailto:ccarter@mit.edu]
Sent: Friday, January 20, 2012 12:52 AM
Subject: Daylight savings time in DatePlus.

Hello,
I need to account for daylight savings time in list of data representing
each hour in year 2010. I would like to correlate that with other data
taken at 15 second intervals in the same year.

In 2010 daylight savings time in the US began on 14 March 2AM.

DateDifference[{2010, 1, 1, 1}, {2010, 3, 14, 1}, "Hour"] (*1728 hours after
beginning of year*)

DateString /@ (DatePlus[{2010, 1, 1, 1}, {#, "Hour"}] & /@Range[1728, 1738])

(*doesn't reflect that 3AM should follow 1AM*)


In hindsight, this is not surprising because daylight savings time
shifts are not standardized intranationally or internationally. I don't
see any clever work-around. Does anyone else?

Craig



W Craig Carter
Professor of Materials Science, MIT








Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.