In which of four zones should lastThu 24:00 be used

Jesper Nørgaard jnorgard at
Wed May 6 21:52:45 UTC 2009

Paul Eggert writes:
> I would guess that all four locations (Egypt, Jordan, Palestine, and
> Syria) are inspired by the same mental ruleset, and if we have good
> evidence that one should be lastThu 24:00, then we should do the same 
> with the other four.

I disagree that interpreting mental rulesets is a good way forward. Rather I
would recommend to check each occurence where it actually matters and 
create the rules based on that.

For Egypt the only difference of the two rules for the period 1995-2009
occurs in 1998 and 2009, concerning Friday of May 1998 and Friday of May 2009. We already saw that in 2009 the change took place on the of April so did not follow Last Thursday of April at 24:00. I have no
information from 1998, but I doubt that Last Thursday of April would be
correct in 1998.

Jordan is really the inspiration for these rule changes and here it must be

In Palestine there are no rules further back than 2008 that are relevant for
this ruleset, and for 2008 and 2009 apparently the rule is Last Thursday of
March at 24:00, although none of them have of April being a Friday so
we won't know yet.

For Syria we could put the rule for years 2007 and 2009, but these years
were non-critical since either rule would work. And since we already had an
exception in 2008 (First Friday of April) I think it is hard to argue they
go by a rule or a mindset.

- Jesper Nørgaard Welen

More information about the tz mailing list