Not much of an author. The data is easily available and it doesn't really matter whether your oil infrastructure is being bombed by night or by day.
It was the 8th AF's initial attacks, in May 1944, which dropped production of synthetic oil from 380,000 tons per month to 200,000 tons. But thereafter both strategic bombing forces made their contribution.
On 27 August 1944 Harris sent the first major RAF daylight heavy bomber raid of the war to Germany. 243 bombers attacked the synthetic oil refinery at Meerbeck (Homberg). At this stage of the war, Bomber Command was more accurate by day than the Americans, though this raid was made through 5-8/10ths cloud on Oboe marking. In September, Bomber Command made nine more daylight raids of 300 or more tons on oil targets in Germany.
Between 16 august '44 and January 1 '45 the number of days and nights on which Bomber Command undertook operations were almost exactly equal, 116 and 115 respectively*, though there were still far more night sorties (43,819 to 28,992). This is partly due to intentionally lower numbers sent by day on each raid. Typically no more than 150 aircraft attacked the same point, as Bomber Command's ORS had calculated that this would maximise accuracy when bombing visually. If more aircraft were sent the accuracy of the "excess" aircraft would be severely degraded by smoke and damage from the preceding units' attacks, and losses might be increased due to the extra time given German antiaircraft artillery to fix the range of the incoming planes. Harris bombed up to the point of diminishing returns and no further. These problems always dogged the US effort.
*Is that another statistic for the WW2 myth thread?