[Zope] DateTime() BUG!

[Kai Hofmann]

> Kai Hofmann writes:
>  > the "enddate" I showed in the "pseudo"-code has been defined as an object=
>  > s=20
>  > property of type "date" - so I assumed the argument is correct - isn't it=
>  > ?
> But then the result *IS* correct, too!
> 
> If you have, as is you example:
> 
>    enddate=<todays date without time>
> then
>    DateTime().lessThanOrEqual(enddate)
> 
> must return "false" most of the day.
> 
> As the name suggests: "DateTime" is date *AND* time.
> "lessThanOrEqual" must take both components into account.

>From my point this is not correct, because of the following points:

1) within the enddate there is no time defined - so it is NOT possible to 
compare the time - following your argument - the result should be a TYPE 
ERROR, because its not possible to compare a date/time pair with a date

2) A date only describes a whole day - so comparing it with a date/time pair 
should always result in a compare of the dates only - because the time is 
out of interest here (its always within the date range).

3) If you want to ignore point 1) and 2) then you MUST add a time to date 
single date - to make the compare work - you can add any time - but it would 
only make sense to add 00:00:00 or 23:59:59 as time (start / end of day)
For a lessThanOrEqual it would be usefull to assume 23:59:59 - for a 
greaterThanOrEqual it would be usefull to assume 00:00:00

So your argument is not acceptable for me - sorry.

Btw. for more about calendrical and time calculation have a look at my site at

http://www.datelib.de/

Greetings

   Kai

-- 
Hofmann Software Engineering International   http://www.hofmann-int.de/
Dipl.-Inform. Kai Hofmann                  mailto:hofmann@hofmann-int.de
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