Answer: First off, that is a beautiful rock!
Also, is there any other information given? Like about rock layer formation, or about this rock specifically or anything?
If there is no other information, then I'd say it took thousands for years for the layers to form, but it depends on the type of rock in the layer.
For example, Igneous rock takes only a few days to form, because all it is is cooled lava, whereas granite takes a few million years to form.
This looks like it might be sandstone or something.
Sandstone takes about 10-100 years to form, so if this is sandstone, then each layer probably look about 100 years to form, and the whole rock with all the layers might have taken thousands of years, but I need more info to be sure.
