How to join several selects

Hello,
I have a 'big' problem:
I have the following table users(name, start_time, end_time), a new row
is set whenever a user logs into a server. I want to know how many
users have logged in EVERYDAY between 2 different dates. The only idea
that I have is making several select (one for each day):
SELECT COUNT(name) FROM users WHERE start_time between "startDate"
and "startDate+1"
SELECT COUNT(name) FROM users WHERE start_time between "startDate+1"
and "startDate+2"
...
I would like to know if its possible to make it in 1 sql statement or
just which is the best efficient way to solve it.
By the way, I use Postgres 7.4.

Thanks!

--
Josep Sanmarti
Analista de Projectes

Grup OpenWired, S.L.
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Tel (+34) 93/410 75 70 - Fax (+34) 93/419 45 91