This was going to be a wild guess with confidence level "1", but then I searched for Vasilopita instructions in English containing "clockwise", and there are lots of them. You have to turn the cake thrice clockwise, you have to cut the pieces clockwise around the circle, etc. (Also, evidently one is supposed to stir Christmas plum pudding clockwise in English culture!) For example:

"Then he spins the plate and chooses one piece to be the first one and counts from there on, clockwise, and gives piece number 1 to the person mentioned in the list at number 1(generally the head of the family), then piece number 2 to the person that is at number 2 in the list and so on…."
http://listentothebeat.wordpress.com/2012/02/05/harumena/

This came to mind, because in translating Vernadsky I had occasion to think about what "clockwise" and "counterclockwise" were called before there were clocks. Vernadsky, talking about conceptions of time and direction in human history, uses forms derived from "посолонь" (and "противосолонь") - which is like "по солнцу" and means "in the direction of the sun", or east to west. It was a challenge to translate this without writing "clockwise"! Had to decide between using the ancient and little-known English terms "deasil" and "widdershins" ("deasil", cognate with "dexter", is actually Celtic), and writing something more descriptive like "in the direction of the sun" and "against the sun". But in describing the cutting of this cake, "clockwise" might be OK.