Every year, as clocks go back in October, millions of people celebrate an “extra hour” of sleep. But how much does this small shift really affect our bodies, our sleep and our mood? According to experts, the autumn transition is much milder than the springtime change - but it’s not entirely harmless. The shift subtly disrupts our circadian rhythm, the internal 24-hour clock that regulates sleep, alertness, hormone production and mood. Related How much sleep do we really need? Here's what the