On Tue, 2010-09-28 at 12:18 -0600, Eric McKeeth wrote: > This is ugly, but it does seem to enforce the constraint I need, of > non-overlapping dates where sharing an endpoint is not considered an > overlap. The period type supports different inclusivity/exclusivity combinations. So, the period: '[2009-01-02, 2009-01-03)' Does not overlap with: '[2009-01-03, 2009-01-04)' Because "[" or "]" means "inclusive" and "(" or ")" means "exclusive". For further discussion, you can join the temporal-general@xxxxxxxxxxxxx mailing list (sign up at http://pgfoundry.org/mailman/listinfo/temporal-general ). If this still does not solve your use case, I'd like to see if it can be modified to do so. Regards, Jeff Davis -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general