Lileks expands his idiom by reading the Internet:
I trust you had a good summer weekend, like the mid-60s Americans above, who are standing around wondering if they are in a cigarette ad or a soft drink ad. Most of all, I hope you didn’t have the Sunday Scaries!
No, I didn’t know the term, either. A google search produced an NBC news story that said “The term ‘Sunday scares,’ although not scientific, describes a common feeling of anxiety that builds up over the course of Sunday afternoon and evening.” The story was titled “The Sunday Scares are Real – This is Why.”
At Nogglestead, we use the term Sundaynitis.
But given our current workstyle and schedules, it’s less of a problem since we’re not working 9 to 5 or 8 to 6 or what have you.