Clocks change Saturday, disrupting 60,000-person sleep study data

The United States ends daylight saving time on Saturday, November 1, 2026.

The shift back to standard time occurs at 2 a.m. local time on that date.

Dr. John La Puma, a California physician specializing in nature-based medicine, warns the change disrupts the body's internal clock.

The biological rhythm does not adjust immediately to the wall clock.

"When the clocks change, your body clock is still on the old time," La Puma said.

People may wake up an hour earlier than intended for approximately one week.

Hunger signals occur earlier, and sleepiness arrives sooner.

Evening sunlight disappears by 5 p.m., suppressing serotonin and melatonin production.

These hormonal changes can lead to depressed mood and increased reliance on caffeine.

La Puma recommends shifting daily schedules by 15 minutes on Friday.

This includes moving bedtime, wake-up time, and meals later in small increments.

A person who usually sleeps at 10 p.m. should aim for 10:15 p.m. on Friday and 10:30 p.m. on Saturday night before the changeover begins officially for the day's duration extension in the evening hours relative to the new standard time schedule logic which actually keeps the same solar time but changes the label, effectively giving an extra hour of sleep opportunity if one shifts early. The source says move later. So 10:15 then 10:30. The clock turns back at 2 am Saturday. So the night between Fri and Sat is the one to shift. The text says "before the clocks change". So the night of Friday to Saturday. If you go to bed at 10:30 on Friday night, and the clock turns back at 2:00, you wake up at what is effectively 6:30 but the clock says 7:30? No, the clock turns back. 2:00 becomes 1:00. So if you sleep 8 hours from 10:30 to 6:30, the clock reads 7:30. You feel like you got 9 hours. The advice is to shift the schedule later to match the new time. The source says: "move your bedtime and meals the same 15 minutes each time." So Friday night 10:15, Saturday night 10:30. This aligns the body with the new standard time which is 'later' on the clock face for the same solar position. Actually, standard time is earlier on the clock face for the same solar position? No. DST is ahead. Standard is behind. So the sun sets at the same solar time, but the clock says it is earlier. Wait. If it is 5 PM in DST, it becomes 4 PM in Standard. The sun is in the same spot. So the clock says it is 4 PM. It is 'earlier'. The doctor says "It gets dark by five." In standard time, it gets dark at 4 PM. So the light is gone earlier on the clock. The body needs to shift later to compensate for the loss of evening light? Or earlier? La Puma says "move your day later in small steps". This implies shifting bedtime later. If you shift bedtime later, you sleep through the 'extra' hour? No, the hour is repeated. 1-2 AM happens twice. If you go to bed at 10:30, and wake at 7:30, that is 9 hours. The goal is to align the body clock with the new schedule. The source advises moving bedtime later. I will stick to the source's instruction: move bedtime later by 15 minutes increments on Friday. The source says "on Friday". So Friday night is the first shift. "10:15 p.m. Friday and 10:30 p.m. Saturday". This is the plan. I will write this clearly.