Re: [LEAPSECS] happy anniversary pips
On 2014-02-12 03:53 PM, Richard Clark wrote: Back in the 1974 oil crisis the US made an 'emergency' change to its DST schedual. I don't recall the legal mechanism used. It was likely an executive order from the President. Is was an act of Congress - the Emergency Daylight Saving Time Energy Conservation Act of 1973 http://www.presidency.ucsb.edu/ws/?pid=4073 It was signed December 15, 1973, to go into effect January 6, 1974. The recent one in 2007, as part of the Energy Policy Act of 2005 http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005 Passed July 29, 2005, Daylight in effect March 11, 2007 -Brooks ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] happy anniversary pips
On 2014-02-12 01:46 PM, Warner Losh wrote: Other systems are less open, and sweep this data under the rug is also a valid conclusion. There's no mystery how Windows handles Leap Seconds - it doesn't. Its off by the Leap Second until it re-syncs to NTP. How the Windows Time service treats a leap second http://support.microsoft.com/kb/909614 Its timezone information is dynamic, held in the Registry: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones For example - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Eastern Standard Time Display (UTC-05:00) Eastern Time (US Canada) Dlt Eastern Daylight Time MUI_Display @tzres.dll,-110 MUI_Dlt @tzres.dll,-111 MUI_Std @tzres.dll,-112 Std Eastern Standard Time TZI BINARY And most entries include a Dynamic DST key - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Eastern Standard Time\Dynamic DST 2006 BINARY 2007 BINARY FirstEntry 2006 LastEntry 2007 These can be updated - (and probably are updated with a Windows Update, I've not verified that.) August 2013 cumulative time zone update for Windows operating systems http://support.microsoft.com/kb/2863058 And can be individually maintained - How to configure the daylight saving time start date and end date for Guatemala in Windows http://support.microsoft.com/kb/918645 This policy of behavior makes Windows a little safer from Leap Seconds and DST changes but its time is almost certainly wrong around changes until it re-syncs. -Brooks ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
