There is usually a screw to adjust at what light level they turn on. So I suppose you could hit the 30 min. mark with some trial and error. But why would you?
You can get an astronomical light switch that replaces the manual light switch that can do that and more based around actual sunrise/sunset time for $30 - it’s a little pricey but they just work.
Yes but I have 4 bulbs outdoors controlled by my $27 switch. Bulbs will fail over time, especially when exposed to the elements and seasonal temperature swings. I can set my lights to turn on off at a fixed time relative to sunset/rise or randomize it +- 30 mins. All with a switch that I bought at a big box store 10 years ago.
that would definitely require them to not be "dumb" anymore.
A simple sunset/sunrise detector can be had from a cheap photo-resistor. 30 minutes prior to sunset sounds like it needs at least a micro controller with a real time clock and a lookup table with sunset times
