"Celia McInnis" <celia@drmath.ca> writes:
> Help - I'm not sure if this is a bug, but I wouldn't call it a feature! :-)
Hardly a bug ... you told it to order by a textual value, why
would you expect a non-alphabetical sort ordering?
I would suggest ordering by EXTRACT(DOW FROM mytimestamp).
You'll probably have to list that as a second GROUP BY item in order
to make Postgres happy with the query.
regards, tom lane