Circadian Clock

So the first thing to notice is that while the mechanical clocks that we make, even your quartz watch can tell time across a vast range of scales from tens of milliseconds to hours minutes and days and months and years. So the brain has many different clocks in order to tell the milliseconds and seconds and to tell the time of days. So one way to think about it is the circadian clock, the clock that tells you what time of day it is and when to arise and when to go to sleep. That doesn't have a minute hand, much less a second hand. In contrast the clock that tells you - the timing device in your brain that tells you, "Hmm, this red light is taking a bit too long to turn." "This traffic light is taking a bit long to turn" or "I think the waiter forgot my coffee." That clock doesn't have an hour hand much less number of days that have gone by. So the brain has different areas, different mechanisms in order to tell time. We don't understand, fully understand, how the brain tells you what the tempo of a song is or when the red light is going to change. But it doesn't seem to have to do with any oscillator-counter mechanisms. It seems to do with neural dynamics which is the fact that patterns of neurons neurons are coupled to each other, neurons are connected next to each other. And when you activate some neurons that group of neurons can activate another group of neurons which can activate another group of neurons. So you can have these evolving patterns of neural activity.