Be careful not to confuse “dawn to dusk” with “sunrise to sunset.” The last sentence of the article can be confusing (and is actually incorrect) as it mentions sunset, but the monument makes it clear the achievement occurred between dawn and dusk.
As pilots know, the FAA considers night time (according to 14 CFR § 1.1) as “the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time.” Morning civil twilight begins when the geometric center of the sun is 6° below the horizon and ends at sunrise. Evening civil twilight begins at sunset and ends when the geometric center of the sun reaches 6° below the horizon.
The title on the plaque pictured on the monument specifically says “Dawn to Dusk,” not “Sunrise to Sunset.” Further, the last sentence of the first paragraph says, Lieutenant Maughan left Mitchell [sic] Field “at dawn” and arrived in San Francisco “one minute before official dusk.”
(The correct spelling is Mitchel, (only 1 “l”) as the field was named in honor of former New York City Mayor John Purroy Mitchel who was killed while training for the Air Service in Louisiana when he fell from his airplane due to an unfastened seatbelt.)
I don’t know what the sun was doing back in 1924, but for reference, morning civil twilight (dawn until sunrise) in Garden City, NY, this morning was from 0450 to 0524 EDT. Evening civil twilight (sunset to dusk) in San Francisco will be 2036 to 2106 PDT.