Lurch wrote (after providing a neat relay-based solution):


I used to work in a building where every fluorescent light unit was
equipped with a pull switch on the lamp. At 12 pm and 7 pm all the
lights were switch off centrally and a tug on the cord was required to
switch each one back on. Quiet neat but not relevant here!


That could be pricey! I'd forget that notion!

Pricey, but not ludicrously so. Units like the Siemens Logo!, the
Mitsubishi Alpha, and their friends sell for about 60-70 notes (may be
cheaper on Ebay, haven't looked). They're baby programmable-logic
controllers, typically 4 independent outputs and 4 or 8 "digital" 240V
inputs. Internal logic gives you all the timed-delay, realtime clock,
ANDs/ORs/NOTs, and similar low-complexity automation control building
blocks you could want. With such a one you end up with momentary-action
press switches at each of your convenient control points, often
configured to have different control actions for a quick press versus a
press-and-hold.

More notes than the OP prolly wants to blow, but hours of harmless geeky
fun. (Such a setup controls the outdoor lighting chez nous, with outdoor
switches able to turn them on but not off, auto-off around 1 a.m.,
switchable indoor buzzer-repeater for the front and back PIRs, and the
like; and a similar module's in place at work for a flexible,
time-of-day/day-of-week-aware hardware access control to control the DC
power to the appliance firewall which allows external Internet access
for a visitor PC, complete with strobing blinkenlight and final-warning
buzzer to remind the dozy pillock using it that their hour of
connectivity-time is about to expire ;-)

Stefek