Do we know how often Ra visited Abydos? Or at least, when was the last time he came to Abydos?
Is there a mention or hint in the movie, during the TV series, in the RPG books or in the novels based on either the movie or the TV series?
The answer does not need to be exact to the minute, an answer saying that he visited every X generations would also suffice.
The novelisation of the Stargate: SG1 pilot episode indicates that it's been "many years" since Ra visited Abydos. It's worth pointing out that the planet itself is largely worthless other than its captive mining population and it's only when the regular shipments of crystalline ore stop coming through like clockwork that he decides to drop everything and see what's going on.
The ship, fully self contained, allowed Ra to fly between the far-flung mining operations he maintained in this corner of the universe.
Although he hadn't been to this small planet for many years, he had come immediately to find out why the quartz shipment had not been made on time.
Later we learn that his visits are considered infrequent, even by one of the villages elders but that they're well aware that he's a "living god". This would strongly imply that Ra comes by every generation or so to make damn sure the Abydosians know who's in charge.
As the third sun surged into the sky marking the official arrival of morning, several thousand of Nagada's citizens had already reached the pyramid, the feared and seldom seen palace of their living god. They gathered into a human sea around the long sloping ramp, the same ramp by which the quartz was delivered to the pyramid. A steady stream of latecomers continued to feed the crowd's numbers, coming over the dunes in a ragged procession that stretched as far as the eye could see.
