Answer:
There are different clues in the story that the season that the story takes place in is winter. First of all, the doctor says there is a light epidemic of flu, and flu epidemics usually take place in late fall or winter
The sentence that includes an allusion is: Like a Grinch, he hated the holidays.
Because it refers to Grinch, a character from a well-known film, who hated Christmas.
