Blood Test Reveals the Time Inside You

Like flowers opening and closing with the sun, our bodies have a rhythm that follows the daily turning of the earth. Processes speed up and slow down; hormones rise and fall; we feel wakeful or tired. But our internal clocks aren't always in sync with the day. By finding out what time our bodies think it is, doctors can time their treatments to work better. And now, there might be a simple way to check the time on our inner clocks.