In uk.d-i-y, Andrew May wrote:

On a related note I am looking for something that will turn on at dusk
but can be set to turn off at a fixed time. Something that in the
summer will turn on at (say) 10:30 when it gets dark and turn off at
(say) midnight and in the winter will turn on at 5:00 when it gets
dark but will still turn off at midnight. With a timer if it is set
for winter times (seven hours) then in the summer it won't turn off
until 4:30 in the morning.

If you want to use "all-standard" components, plug a light-sensitive lamp
or switch (an "on at dusk, off at dawn" jobbie) into a timer which comes
on earlier than any possible dusk - say, 3pm - and goes off at the time
you want - say, midnight. By the magic of switches-in-series, the lamp
will light only when (a) it is Dark Enough, and (b) it's in the timer's
'on window'. Obviously you have to put the timeswitch first in the chain,
so it gets supply 24h a day.

For fancier switching I've used a "logic controller" like the Siemens Logo!
to handle multiple circuits, PIRs, external on-but-not-off switches,
overrides accessible only from inside the house, and so on. But then I'm
a geek...

HTH, Stefek