There are no trains running at this time of the night.The question was, "Shouldn't 'at this time of the night' be 'at this time of night'?" The publisher asked me for my opinion. My opinion—that is, my immediate impression, my naive native-speaker instinct—was that both expressions are used at about the same frequency. But when I compared the hit counts at Google, the "time of night" version was a half-dozen times more frequent:
"at this time of night" 19,400Because the "time of the night" version is not unusual or nonstandard, I did not recommend that this entry be revised the next time the dictionary is reprinted.
"at this time of the night" 2,760
"at that time of night" 4,780
"at that time of the night" 925
(December 26, 2002)