[MASSMAIL]help with a particular multi-table query

I'm attempting a three column select from two tables, where only a
single column from each of the tables matters.

t1.date and t2.time are both timestamptz.

I want the three columns to be:

t1.date::date

t1.date - lag(t1.date,1) over (order by date asc) days,

and count(t2.time) from the interval lag(t1.date,1) and t1.date.

but that syntax of course fails do to the placements I've tried for thae
between.

I tried a sub-query but got what looked like an outer join.

I want exactly count(*) from t1 rows in the result.

What trick am I missing?

-JimC
-- 
James Cloos <cloos@jhcloos.com>
            OpenPGP: https://jhcloos.com/0x997A9F17ED7DAEA6.asc