The Dark Of The Moon
"Was the dark of the moon on the sixth of June..." when The Convoy began. But in what year? Since "Convoy" was released in 1975, the event itself must have been in the recent past.
I started my research at a “moon phases” page, which had a visual display of the phase of the moon for every day in a selected month. Since The Convoy could not have begun any later than 6 June 1975, I began there.
In 1975, the new moon — the “dark of the moon” — occurred on the 9th day of June. On the 6th of that month, a thin silver of light could still be seen, which isn't quite "dark". Maybe on the 7th, as two days before a new moon the disc is almost invisible. But not quite, if you're picky.
So, what date better fit the description in the song? 1970, when the new moon occurred on the 4th. The visible crescent was beginning to appear by the 6th, but at least the disc would have been darker than it had in 1975.
However, a new moon did actually occur on the 6th of June 1959. But that date is too far in the past to be possible. And the next new moon to occur on the 6th will be in 2005, assuming that Earth is not destroyed in a millennial cataclysm. :)
Crispy Critter Chris Bergman reports that, “According to The Library of Halexandria,
“The Dark of the Moon is traditionally the last three days of the Lunar cycle, immediately preceding the New Moon, and the time when the night sky is notably absent the presence of the Moon.”
This fits 1975 as June 6 would still be in the “Dark of the Moon”. The 55 mph speed limit was enacted in 1974, so it [The Convoy] could not have been 1970.