Full Idea
Forty times a second an electrical pulse is sent across the brain. …The internal sense of time in us is created by such internal regular, iterative events as neural firings.
Gist of Idea
Our sense of time may arise from regular brain pulses
Source
G Lakoff / M Johnson (Philosophy in the Flesh [1999], 10)
A Reaction
Hard to prove, but they describe it as just a hypothesis. I've always had a better than average knack of estimating the time of day, which must have some basis.
Book Reference
Lakoff,G/Johnson,M: 'Philosophy in the Flesh' [Basic Books 1999], p.138