Pokémon Sleep has announced details about the November 2023 Good Sleep Day Event which takes place from Sunday, November 26th, 2023 to Wednesday, November 29th, 2023 at 3:59 a.m.

The Fourth Good Sleep Day Event

Note: Drowsy Power on the night of a full moon during the Fourth Good Sleep Day event will be quadrupled! During Good Sleep Day events from now on, the multiplier for Drowsy Power will depend on the day of the week. (Please see below for details.)

Rest your very best on the night of a full moon!
This event is held once a month for a total of three days: on the day of the full moon and the days before and after it. During this month’s Good Sleep Day, Drowsy Power will be multiplied by 1.5, and on the day of the full moon (November 27), it will be multiplied by 4. Let’s all try to get lots of sleep during the event and research loads of Pokémon sleep styles!

Day 1: Sunday, November 26, at 4:00 a.m. to Monday, November 27, at 3:59 a.m.​
Day 2 (the night of the full moon): Monday, November 27, at 4:00 a.m. to Tuesday, November 28, at 3:59 a.m.​
Day 3: Tuesday, November 28, at 4:00 a.m. to Wednesday, November 29, at 3:59 a.m.

How to Progress in the Event

Participating in the event is easy! Simply press the “Sleep” button before going to sleep during the event period to track your sleep. A variety of event-related effects will be triggered during your sleep research.

— Night of the full moon (Nov 27) —
Drowsy Power ×4
Pokémon Sleep EXP ×3
Bonus Sleep Points +1000

— Other days (Nov 26, Nov 28) —
Drowsy Power ×1.5
Pokémon Sleep EXP ×2
Bonus Sleep Points +500

Multipliers for Drowsy Power

From now on, the multipliers for Drowsy Power on the night of a full moon during Good Sleep Day events will depend on the day of the week. The planned multipliers will be as follows:

Drowsy Power Multipliers on the Night of a Full Moon

Monday: ×4
Tuesday: ×3
Wednesday: ×2.5
Other days: ×2

Notes: Drowsy Power on the days before and after a full moon will always be multiplied by 1.5 regardless of the day of the week.
The above multipliers depending on the day of the week are subject to change.

Notes about Good Sleep Day

• [Important] Each day of the Good Sleep Day event rolls over at 4:00 a.m.
• Event bonuses apply only to sleep data tracked within the event period.
• If you wait to report sleep data tracked before the event begins, and select “Review Later” during the event, event bonuses will not be applied.
• If you wait to report sleep data tracked during the event, and select “Review Later” after the event has ended, event bonuses will be applied.
• You can only receive bonus sleep points once per day. You will not receive bonus sleep points for the second sleep session in a day.
• Event bonuses do not apply to sleep tracking during the tutorial.
• Event bonuses will be triggered regardless of which site you conduct your sleep research in.
• The effects of incense stack with Good Sleep Day effects. If you use Growth Incense on the night of the full moon, EXP gains will be multiplied by 6 (×3 from the full moon bonus and ×2 from the Growth Incense bonus).

Source: https://www.pokemonsleep.net/en/news/4076/