Chacham's Journal: Puzzle: Daily changed values, how many days to figure out?

A puzzle? Perhaps, but not a hard one. I was thinking about this last night while riding my bicycle.

There are four binary switches making up an unknown setup. Every day, a different switch is flipped, and the prior day's switch is flipped back. It is unknown which switch is flipped, but the order of flippage repeats every four days.

How many days would it take to figure out the original code?

If instead two switches were flipped each night, with at least one switch being different from the prior night (the other being the same or different), and all combinations used, then repeated, how many days would it take to figure out the original code? What about three following the same logic?

Four should be very easy.

Now, make the switches dials with ten values each. Same questions.

As i said, nothing special, but interesting on a night time ride.