When dog days doesn't mean dog's days...

Dog days

The meaning is –The hottest days of summer, often when it’s hard to work or be productive because of the heat. It can also refer to a sluggish or unproductive period.

Similar idioms –

• The heat is on

• In the doldrums

Examples

1. During the dog days of August, I barely want to leave the house.

2. Business is always slow during the dog days of summer.

中文意思是 – 盛夏酷暑期；也可指無精打采或停滯不前的時期 / 盛夏酷暑期；也可指无精打采或停滞不前的时期