Light, especially sunlight, is the strongest “time giver” (zeitgeber) for circadian rhythms and sleep. Melanopsin-containing retinal ganglion cells detect light and signal the central circadian clock, called the suprachiasmatic nucleus. Bright light in the morning advances your clock, while light at night delays it. Get sunlight/bright light exposure for 2–10 minutes right after waking, and avoid bright lights 1–2 hours before bed for optimal sleep.

• Magnesium, theanine, apigenin and melatonin are natural supplements that may aid sleep for some. However, they can disrupt circadian rhythms or have side effects, so consult a doctor before use. 
• For some, naps and “non-sleep deep rest” like meditation or hypnosis reset focus and promote sleepiness. They are skills that improve with practice.
• It is easier to stay awake than force oneself to sleep. Relaxation practices using the breath and body help calm the mind for sleep.

Circadian rhythms arise from the central clock in the brain but impact the timing of physiological events throughout the body. They regulate hormones, body temperature, metabolism, hunger, immune function, and more. Disrupting them can lead to weight gain, diabetes, depression, and dementia over time.

The mind continues analyzing, planning and problem-solving (D-P-O), especially if excessively stimulated before bed. Relaxation techniques help calm the mind by focusing it on the body and breath. They can reset wakefulness-promoting neuromodulators, easing the transition to sleep.

• Get sunlight exposure, ideally first thing after waking. Use artificial light if needed. This sets your circadian clock and hormonal rhythms for the day.
• Avoid overhead and electronic lights, especially blue light, 1–2 hours before bed.
• Stick to a consistent sleep schedule, even on weekends. Our bodies like predictability.
• Keep a consistent exercise schedule during the day or afternoon. Avoid intense workouts close to bedtime. Exercise is stimulating.  
• Stay away from caffeine, nicotine, and alcohol close to bedtime. Do something calming like reading, or a warm bath.