I don't ponder much on Dates, DateTimes etc, but I just had one interesting image flash through my head��and was curious how correct it sounds, or if I'm completely off base.
So who remembers the old arcade game "Moon Buggy" ?
Now imagine that passing beneath your wheels is a hyper-fast terrain of DateTime��.
Levels are days marked "A" , "B", "C", "D", "E" at *fixed* points on the DateTime terrain, representing when a particular Date begins.
As your day progresses dealing with obstacles in your path the *point* of Date separation approaches you.
In your own timezone you know what Date it is by when your wheels pass over a Date marker.
Now if someone in the US wants to know the date in New Zealand,��
that is like attaching a scanning laser beam to the front of the buggy.����
How far ahead it scans depends on the *difference* between time zones.
As the DateTime terrain passes beneath your wheels, the fixed Date point approaches you, and when it touches your lazer scanner, the Date changes in the other timezone.
So the way to find the date in another timezone,��
is not to give a Date a timezone, but rather to add the difference in timezones to your DateTime��
to get the DateTime in the target country to compare that with timezoneless-Date.
cheers -ben