Let's assume that I wash my car every Saturday at noon. How do I say it using the word schedule:
I wash my car at/by/on schedule.
Update: It's not about doing something on a regular basis. It's about doing something on schedule — at an exactly defined day and time every week. If I say "I wash my car regularly", it simply means that I don't forget to wash my car, but doesn't imply I do it every time at the same time.
Best Answer
You can use to a schedule to mean you have a preplanned date/time when you will wash your car.
A more wordy way to say it would be