I remember my salad days when I was young and inexperienced.

The dog days of summer are always so hot and humid.

I will finish the project in a few days.

In days of yore, people used to travel by horse and carriage.

Back in the days, people used to communicate through letters.

The hikers trekked through the rugged trails for days on end to reach the summit, driven by their passion for adventure.

Day after day, she practiced the piano.

The weather varies from day to day.

The new fashion trend was just a nine days' wonder.

I have been working late for three days in a row.