The San Francisco earthquake of 1989 happened at 5:04 Pacific time, well before sunset.
The Northridge quake in LA in 1994 happened in the middle of the night, well before sunrise.
The Whittier Narrows quake of 1987 happened about 8:30 am, if I recall correctly.
Does he really mean within a few hours of dawn or dusk, as opposed to high noon? Or is this is theory not supported by evidence?
I don't know about you, but I was in that one. It was at about 4:30 in the morning, not really middle of the night, but pre-morning, is how it felt to me. I felt from hundreds of miles away '89 quake in San Francisco, and it was at five on a fall day -- sunset was only 90 minutes out. I would classify the time as near sunset, near the end of the day. If it was an hour or two earlier -- 3 or 4, at that time of year, no. But 5-ish, yeah.
I guess he means within six hours of either dusk or dawn.
Within 12 hours.