NavList:

Franks wrote

I made a map (attached to this message) of US headlight laws for evening "light up" time. Not fit for navigation and not fit for legal argument! In many states headlights should be turned on at sunset. But what time is sunset? In other states headlights should be turned on by 30 minutes after sunset. Nice that they inform us that it's "exactly" 30 minutes after sunset, regardless of the duration of civil twilight which depends on both driver's latitude and also the Sun's declination. And again, what time is sunset? 

There seems to be one exception to the two options for the law among US states. Various compilations list the rule for the state of Maryland, but they seemed a bit contradictory. I found a statement of the rule from the Maryland government, and it appears they require headlights "at night" (good for them; they punted!). What does "night" mean legally? It may mean (in evening hours) after the end of civil twilight, which is a legally accepted time, or does it just mean whatever the police officer says that it means when you're ticketed??

In NZ  Peeping or peering into a dwellinghouse is an offence if it is done at night.  The Summary Offences Act 1981 defines "night" as the period from the end of one hour after sunset to  the beginning of  one hour before sunrise.

The lack of a definition of "sunset" does not matter in NZ - all the constable has to do is testify that he could not clearly see a pedestrian 100m away.

If the cyclist had lots of money he could employ a good lawyer and an expert witness to bamboozle the court. The case would be dimissed because the law makers had not defined if they meant the Theoretical setting  of the sun or the Visible setting. As the policemen was grilled over the Admiralty Manual of Navigation 1938  volume II he would no doubt wish that he had ignored the cyclist.