Subject: Re: Snapshot Report - 27 March tar_files
To: Martin Husemann <>
From: Michael L. VanLoon -- Iowa State University <>
List: current-users
Date: 03/29/1994 23:55:03
>> 3.  I've seen lots of stuff about timezone's being a bit dodgy,
>> especially with most European timezones changing over to DST on the
>> 27th March.  I must say that that was NOT the case for me - pumpy is
>> running off the /usr/share/zoneinfo/GB-Eire timezone file,
>> (symbolically) linked to /etc/localtime, the CMOS clock is running off
>> GMT, and the kernel is compiled with "timezone 0".

>I use /usr/share/zoneinfo/MET as /etc/localtime and have the kernel configured
>timezone        -1 dst 4
>(My wife is running DOS on this machine for doom sometimes ;-)
>I set this strange dst value after diging in some old ultrix(?) man pages.
>There were several dst-changing-method listed and 4 was the code for the 
>central europe one.

This gave me an idea... I use an Ultrix box every day, so why not...

Now, I don't know how closely this applies to NetBSD since Ultrix is
based on a much older version of BSD, and this isn't for the kernel
config, but for an envar of timezone values, but it's at least
somewhat enlightening on possible meanings for these things.  Could
someone in the know shed light on how accurately this models the
timezone stuff in the kernel config?  When I did "man timezone" this
is what I got (portion of this quoted from the DEC MIPS Ultrix 4.3a
timezone(3) manpage, slightly hacked by me):

	 STD offset [DST [offset][,start[/time],end[/time]]]

     the components of the string have the following meaning:

     STD and DST    Three or more characters that are the designation for the
		    standard (STD) or summer (DST) time	zone. Only STD is
		    required; if DST is	missing, then summer time does not
		    apply in this locale. Upper- and lowercase letters are
		    explicitly allowed.	Any characters except a	leading	colon
		    (:), digits, comma (,), minus (-), plus (+), and ASCII
		    NUL	are allowed.

     offset	    Indicates the value	to be added to the local time to
		    arrive at Coordinated Universal Time. The offset has the


		    The	minutes	(mm) and seconds (ss) are optional. The	hour
		    (hh) is required and may be	a single digit.	The offset
		    following STD is required. If no offset follows DST, sum-
		    mer	time is	assumed	to be one hour ahead of	standard
		    time. One or more digits may be used; the value is always
		    interpreted	as a decimal number.  The hour must be
		    between zero and 24, and the minutes (and seconds) - if
		    present - between zero and 59. If preceded by a "-", the
		    time zone is east of the Prime Meridian; otherwise it is
		    west (which	may be indicated by an optional	preceding

     start and end  Indicates when to change to	and back from summer time.
		    Start describes the	date when the change from standard to
		    summer time	occurs and end describes the date when the
		    change back	happens. The format of start and end must be
		    one	of the following:

		    Jn	    The	Julian day n (1	< n < 365). Leap days are not
			    counted.  That is, in all years, including leap
			    years, February 28 is day 59 and March 1 is	day
			    60.	It is impossible to explicitly refer to	the
			    occasional February	29.

		    n	    The	zero-based Julian day (0 < n < 365). Leap
			    days are counted, and it is	possible to refer to
			    February 29.

		    Mm.n.d  The	nth d day of month m (1	< n < 5, 0 < d < 6, 1
			    < m	< 12). When n is 5 it refers to	the last d
			    day	of month m. Day	0 is Sunday.

     time	    The	time field describes the time when, in current time,
		    the	change to or from summer time occurs. Time has the
		    same format	as offset except that no leading sign (a
		    minus sign (-) or a	plus sign (+)) is allowed. The
		    default, if	time is	not given, is 02:00:00.

     As	an example of the previous format, if the TZ environment variable had
     the value EST5EDT4,M4.1.0,M10.5.0 it would	describe the rule, which went
     into effect in 1987, for the Eastern time zone in the USA.	Specifically,
     EST would be the designation for standard time, which is 5	hours behind
     GMT. EDT would be the designation for DST,	which is 4 hours behind	GMT.
     DST starts	on the first Sunday in April and ends on the last Sunday in
     October.  In both cases, since the	time was not specified,	the change to
     and from DST would	occur at the default time of 2:00 AM.

     The timezone call remains for compatibility reasons only; it is impossi-
     ble to reliably map timezone's arguments (zone, a `minutes	west of	GMT'
     value and DST, a `daylight	saving time in effect' flag) to	a time zone


 Michael L. VanLoon                 Iowa State University Computation Center                    Project Vincent Systems Staff
  Free your mind and your machine -- NetBSD free Un*x for PC/Mac/Amiga/etc.