Must be a political choice, then. But the actual change to winter or summer is determined by the earth and the sun, at the precise second when the sun is directly above the tropic of cancer or capricorn (I misspoke in the earlier post -- I meant summer or winter solstice, not equinox). That time and day can vary each year. The change to autumn or spring is marked by the precise time when the sun transits the equator and enters the other hemisphere.

This year, the solstice occurs at 00:48 GMT on June 21.

-----Original Message-----
From: Jesper Nielsen [mailto:jesniel@...]
Sent: Tuesday, June 01, 2004 1:49 PM
To: BoundaryPoint@yahoogroups.com
Subject: Re: [BoundaryPoint] Four seasons quadropoints

Well, in Denmark is has always been on June 1.

June 20 or 21 is the longest day.

Jesper

----- Original Message -----

From: Flynn, Kevin

To: 'BoundaryPoint@yahoogroups.com'

Sent: Tuesday, June 01, 2004 9:08 PM

Subject: RE: [BoundaryPoint] Four seasons quadropoints

It wouldn't be on June 1; it would be at the precise clock time on June 20 or 21, whenever the equinox is. The official start of the new season is the precise point in time when the sun crosses the line of the equator, not a particular day.

-----Original Message-----
From: Jesper Nielsen [mailto:jesniel@...]
Sent: Tuesday, June 01, 2004 10:17 AM
To: BoundaryPoint@yahoogroups.com
Subject: [BoundaryPoint] Four seasons quadropoints

Sounds like a pizza, doesn't it?

Well, have you wondered where you can stand in four seasons at the same time? Probably not. Well here is the answer:

1) On the Columbian-Brazil border:
http://tinyurl.com/25anb

2) Internal Brazil: Boundary of Para and Amapa:
http://www.brazilhouston.org/ingles/fusohora.gif
http://bloggle.com/coffee/brazil-map.jpg
http://tinyurl.com/2qsj8

3) Internal DR Congo: Boundary of Equateur and Orientale
http://tinyurl.com/3hmmj

4) On DR Congo-Uganda border:
http://tinyurl.com/2c5ck

Explanation?

From June 1st N of Equator starts summer, S of Equator starts winter

Each N-S boundary about also marks a time zone boundary

so W of the line is one hour behind E of the line.

So if you stand in

Columbia N of equator at 00.30 am Columbian time it's summer

Columbia S of equator at 00.30 am Columbian time it's winter

Brazil N of equator at 00.30 am Columbian time it's spring

Brazil S of equator at 00.30 am Columbian time it's fall

How about that?

The bad news are that all four points seems hard to reach.

Jesper