TX Revisited [Oh No!] [was Re: TZ... Again (OT)]

[Simon Bowring]

On Tue, 28 Mar 2000 22:35:47 -0800, Marty Abrego wrote:

>>set TZ=gmt0bst,3,-1,0,7200,10,-1,0,10800,3600

It's been pointed out to me that this string is wrong (thanks
Brian Morrison!).

Apparently the UK does not change time at 02:00, but at 01:00! 

Nearly all UK based computer systems I have worked on are configured
to change at 02:00 as the TZ string I published.

However, according to http://greenwich2000.com/time/info/bst.htm,
it starts at 1 am ("this week"):

If correct, and I assume it must be, the TZ string should be:

  Set TZ=gmt0bst,3,-1,0,3600,10,-1,0,7200,3600

Note the difference (exactly when the clock changes) is not likley 
to be significant for 99.999% of all computers!

Simon
---

GMT - Greenwich Mean Time

Frequently Asked Questions

When will British Summer Time (BST) be in force?

The Summer Time Act 1972 defined the period of British Summer Time to
start at 2 am (GMT) on the morning of the day after the third Saturday in
March or, if that was Easter Day, the day after the second Saturday. It was
to end at 2 am (GMT) on the day after the fourth Saturday in October.

The duration of British Summer Time (BST) can be varied by Order of
Council and in recent years has been changed so as to bring the date of
the start of Summer Time into line with that used in Europe.

The rule for 1981-1994 defined the start of Summer Time as the
last Sunday in March and the end as the day following the fourth
Saturday in October. The time of change was altered to 1 am
(GMT).

There is no rule for the dates of Summer Time (BST) for the years 1995,
1996 and 1997.

The agreed dates were:

     For 1995 BST started on March 26 and ended on October 22

     For 1996 BST started on March 31 and ended on October 27

     For 1997 BST started on March 30 and ended on October 26

     In 1996 all clocks in Europe were changed the same date for the first time.

From 1998 BST will be kept from the last Sunday in March until the last
Sunday in October. This has been adopted as a directive from the
European Parliament and will be effective from 1998-2001 inclusive.

     1999: March 28 - October 31

     2000: March 26 - October 29

     2001: March 25 - October 28

     All changes to be at 1 am GMT. 

Source: Royal Observatory Greenwich