Поиск допустимых интервалов

last_hour = lines[0]
skiped_hour = 0
sum_hour = 0
for(hour in lines[1:]):
  if hour - last_hour + skiped_hour > 5:
    # скипаем до следующего цикла
  sum_hour += 1
  skiped_hour += hour - last_hour -1

with a(x) as (values
('25.10.2017 9:00:00'),
('25.10.2017 10:00:00'),
('25.10.2017 12:00:00'),
('25.10.2017 13:00:00'),
('25.10.2017 14:00:00'),
('25.10.2017 15:00:00'),
('25.10.2017 16:00:00'),
('26.10.2017 8:00:00'),
('26.10.2017 9:00:00'),
('26.10.2017 10:00:00'),
('26.10.2017 11:00:00'),
('26.10.2017 13:00:00'),
('26.10.2017 14:00:00'),
('26.10.2017 15:00:00'),
('26.10.2017 16:00:00')),
t as (select to_timestamp(a.x, 'dd.mm.yyyy hh24:mi:ss') as t from a),
tt as (select t, extract(doy from t)::int as doy from t),
ttt as (select *, tt.t - lag(tt.t) over(partition by tt.doy order by tt.t) as delta from tt),
tttt as (select *, (delta is null or delta > '1 hour'::interval)::int as sog from ttt),
ttttt as (select *, sum(sog) over(order by tttt.t) as gid from tttt)

select min(t) as start, max(t) as end, gid 
from ttttt group by gid order by start