The Pokémon Sleep Eevee Week 2023 event takes place from Monday, November 20th, 2023 at 4:00 a.m. until Monday, November 27th, 2023 at 3:59 a.m. Your chances of encountering an Eevee and its evolutions increase, especially with the Eevee Incense you'll receive as a reward!

Eevee Week 2023

The Eevee Week 2023 event will begin at 4:00 a.m. on November 20! Eevee Week 2023 is a week-long event to celebrate Eevee Day (November 21), during which Eevee and its Evolutions are more likely to gather to sleep! You’ll be able to encounter Pokémon of different sleep types regardless of your own, and Eevee and its Evolutions will be more likely to appear. If you’re lucky, you might even meet a Shiny Eevee!

Also, if you conduct sleep research on Eevee Day (November 21), you can get 1,121 bonus sleep points. You can get nice rewards like Eevee Incense through special missions, which will be available in addition to the usual missions.

And during this Eevee week, all of your helper Pokémon’s main skills will have a higher chance of being triggered!

We hope you enjoy this great work from your helper Pokémon!

Day 1: Monday, November 20, at 4:00 a.m. to Tuesday, November 21, at 3:59 a.m.
Day 2 (Eevee Day): Tuesday, November 21, at 4:00 a.m. to Wednesday, November 22, at 3:59 a.m.
Day 3: Wednesday, November 22, at 4:00 a.m. to Thursday, November 23, at 3:59 a.m.
Day 4: Thursday, November 23, at 4:00 a.m. to Friday, November 24, at 3:59 a.m.
Day 5: Friday, November 24, at 4:00 a.m. to Saturday, November 25, at 3:59 a.m.
Day 6: Saturday, November 25, at 4.00 a.m. to Sunday, November 26, at 3:59 a.m.
Day 7: Sunday, November 26, at 4:00 a.m. to Monday, November 27, at 3:59 a.m.

How to Progress in the Event

Participating in the event is easy!
Simply tap the “Sleep” button during the event period to track your sleep.
A variety of event-related effects will be triggered during your sleep research.
Note: Event bonuses can be triggered in any area for this event.

Event Bonuses

— Eevee Day (November 21) —
• Greater encounter chance for Eevee and its Evolutions during sleep research
• Many Pokémon of different sleep types will appear during sleep research regardless of the researcher’s sleep type for the day.
• If you’re lucky, you may encounter a shiny Eevee.
• +1,121 bonus sleep points
• Main skills for all helper Pokémon are 1.5 times more likely to be triggered.

— Other Days (November 20 and November 22−26) —
• Greater encounter chance for Eevee and its Evolutions during sleep research
• A few Pokémon of different sleep types will appear during sleep research regardless of the researcher’s sleep type for the day.
• If you’re lucky, you may encounter a shiny Eevee.
• Main skills for all helper Pokémon are 1.5 times more likely to be triggered.

— Pokémon That Are Easier to Encounter Throughout the Event —
During the event period, you’ll have a greater chance of meeting the following Pokémon!
Much Greater Encounter Chance: Eevee
Greater Encounter Chance: Vaporeon, Jolteon, Flareon, Espeon, Umbreon, Leafeon, Glaceon, Sylveon

Notes: The much greater encounter chance for Eevee applies to all areas.
The greater encounter chance for other Pokémon applies only to the separate areas where each Pokémon appears.

Notes about Eevee Week

• [Important] Each day of the Eevee Week 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.

Source: https://www.pokemonsleep.net/en/news/3994/