"At schedule" vs. "by schedule" vs. "on schedule"

Question

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.

Answer 1

You can use to a schedule to mean you have a preplanned date/time when you will wash your car.

I wash my car to a schedule.

A more wordy way to say it would be

I wash my car in accordance with my/the/a schedule.

Answer 2

I wash my car every Saturday like clockwork.

Answer 3

On schedule is the right definition. It sounds a bit unusual for the habit of washing your car. It refers more to prefixed arrangements that have to be carried out on the agreed time.

For your habit I'd say:

I am used to washing my car every Saturday at noon.

Answer 4

Habitual: Being such by habit.

Or any of its subsequent synonyms (constant, persistent, continual, continuous, perpetual, nonstop, recurrent, repeated, frequent).

I habitually wash my car according to schedule (every Saturday at noon).

Answer 5

Instead of 'on schedule', I would say 'on a schedule'

I wash my car on a schedule

On a schedule implies that you have some schedule for washing you car.

Answer 6

Consider "on time" and "on a timely manner (or basis)."

I wash my car every Saturday on time.

I wash my car every Saturday on a timely basis.