
Here are some differences in how the datetimes are handled by Sybase and
Postgres95 adaptors.

Sybase offers the dbdatecrack() function that splits a DATEREC structure in
the year, month, day, hour, minute and second components. These are used to
create a NSCalendarDate object using the EOAdaptorChannel's
+dateForAttribute:year:month:day:hour:minute:second:zone: method. This method
creates the date using the attribute's server time zone and then sets the
client time zone. If neither of these exists the local time zone is used
instead.

The above schema cannot be used by the Postgres95 adaptor because the `dt'
type uses integers that are offsets from January 1, 1970 so we can't use a
similar function that splits such an offset in the components parts relative
to the server time zone. To be able to handle different server and client time
zones we write all the time values relative to GMT.
