Wiktionary
n. a time when media organisations publish trivial stories due to the lack of more substantial topics.
Usage examples of "slow news day".
True, on a slow news day, anchor Rick Sanchez can make a routine domestic shooting sound like a sniper attack on an orphanage.
It appeared that the reporter's editor had only printed the story because of a slow news day and a lack of editorial to fill up that day's paper.
Were it to be a slow news day--Friday in Washington often was-- it might get a minute and a half on one or two of the evening news shows.
The footage had everything: drama, death, a courageous (and attractive) reporter, and would run as the lead piece for the evening news broadcast for this otherwise slow news day, to be repeated by all the network morning shows the next day.
It was the second major political lie of the day - a slow news day to be sure.