How do I reach the clock tower?

Hint 1 of 6:

Do you see any access key that looks appropriate for a clock?

Hint 2 of 6:

There's one that's a time of day.

Hint 3 of 6:

It's 2:40, to be exact.

Hint 4 of 6:

You need to set the time on the clock to 2:40.

Hint 5 of 6:

You can set the time with the controls near the edge of the water.