The 123 sleep rule works by helping you wind down for the night and helps improve your sleep and sleep quality.
The 123 sleep rule is actually the 3-2-1 sleep rule or even the 10-3-2-1-0 sleep rule..
The 3-2-1 sleep rule and the 10-3-3-2-0 sleep rule are pre-sleep routines which help you to wind down and improve your sleep quality.
For the 3-2-1 sleep rule method it involves stopping heavy meal consumption 3 hours before bed, stopping work/stimulating activities 2 hours before bed and stopping screen time 1 hour before bed.
As for the 10-3-2-1-0 sleep rule it is a more detailed version of the 3-2-1 sleep rule which includes no caffeine consumption 10 hours before bed.
To use the 3-2-1 sleep rule.
3 hours before bed you stop eating heavy meals or drinking alcohol.
2 hours before bed you stop working and engaging in mentally stimulating activities.
And 1 hour before bed you turn off all screens, which includes computer screens, phones, tablets and Televisions to minimize blue light exposure.
To use the 10-3-2-1-0 sleep rule.
10 hours before bed you stop consuming caffeine.
3 hours before bed you stop drinking alcohol or stop eating.
2 hours before bed you stop working or doing anything that is mentally demanding.
And the 0 is for hitting the snooze button zero times in the morning.