Yes, I used the wrong call. This should work.
template:
- binary_sensor:
- name: Night Time
unique_id: night_time
state: >
{{ not '06:30' <= as_timestamp(now()) | timestamp_custom('%H:%M') <= '23:00' }}
Anwyas to explain the code…
'06:30' <= as_timestamp(now()) | timestamp_custom('%H:%M') <= '23:00' verifies the time is between 630 and 2300.
the not in front of that chooses the opposite time… I.e. night.