In Jens Hoyrup's paper “A HISTORIAN’S HISTORY OF ANCIENT EGYPTIAN SCIENCE”, an essay review of Clagett's Ancient Egyptian Science, on page 18 Hoyrup claims:
“The Karnak clock assumes the change of the length of night to be uniform from solstice to solstice – in the idiom used to discuss Babylonian astronomy, it constitutes a zigzag-function (which should not be taken as evidence of a borrowing, cf. note 25).”
This claim is important because, the Karnak water clock is dated to the 14th Century BCE making it contemporary with the Rhind Mathematical Papyrus. The zig-zag function is associated with Babylonian System B mathematical algorithms. It is believed the water clock was based on an earlier design. However, at 14th Century BCE, it is some 1,000 years prior to the era of Babylonian Mathematical astronomy.