Timezone boundaries

[Oscar van Vlijmen]

This was part of a mail from Oscar van Vlijmen:
> [...] Theoretical timezones:
> Take [0;15W), [15;30W),..., [165;180W), [180E;165E),..., [15E;0E)
> Times in hours from UT. [ means including, ) means not including.
> 0-15E   +1 [...]

Gwillim Law wrote:
Minor correction:  what I was trying to express was that ships at sea should
use UTC between 7.5 degrees E and 7.5 degrees W, UTC+1 between 7.5 degrees E
and 22.5 degrees E, etc.

Oscar replies:

Gwillim could be very right. Looking carefully at for instance the
"standard time zones" map from HM Nautical Almanac Office and the map
"standard time zones of the world" from the CIA world factbook (both of
which maps btw are not up to date), then I can see that they reflect the
situation Gwillim depicts.
Another flaw in my list was the absence of a UT+0 zone.

Thanks for all your remarks.
Here is the new list:

Theoretical timezones:
Times in hours from UT.
[ ] means including, ( ) means not including.
This rather arbitrary distinction is needed for mathematical reasons, i.e.
when implementing in a program.
longitude range   time offset
[7.5W-7.5E)  +0
[7.5E-22.5E)  +1
[22.5E-37.5E)  +2
[37.5E-52.5E)  +3
[52.5E-67.5E)  +4
[67.5E-82.5E)  +5
[82.5E-97.5E)  +6
[97.5E-112.5E) +7
[112.5E-127.5E)  +8
[127.5E-142.5E)  +9
[142.5E-157.5E)  +10
[157.5E-172.5E)  +11
[172.5E-180E)  +12
(172.5W-180W]  -12
(157.5W-172.5W]  -11
(142.5W-157.5W]  -10
(127.5W-142.5W]  -9
(112.5W-127.5W]  -8
(97.5W-112.5W]  -7
(82.5W-97.5W]  -6
(67.5W-82.5W]  -5
(52.5W-67.5W]  -4
(37.5W-52.5W]  -3
(22.5W-37.5W]  -2
(7.5W-22.5W]  -1

Oscar van Vlijmen
2000-01-05