Treatment involves three to four hours of therapy a day.

The program involves eight hours of sailing, six days a week.

The job paid well, but it involved long hours.

Each round-trip involved 35 flying hours and took four days to complete.

It involves three or four full days a month plus two hours a week on the phone.

Bring an extra driver if your trip involves more than six hours of driving time.

"These days that involves flexible working, late hours and weekends."

The program itself involves approximately 20 hours a week of formal language instruction.

It furthermore involved "buying" flying hours at a fixed rate.

Tickets are always scarce and some journeys involve hours of standing.