Date-Based Events

Date-based events are in-game events triggered only on specific dates. Unlike Mystery Gifts, these events are specifically triggered by time checks within the game's script. They can occur each year within their specified date range unless they're either set to run on specific years or removed from the game in a future update.

October

First witnessed in versions 2.1 to 2.2.2, Pokémon Sardonyx contains a few minor changes lasting through the entire month of October.

• Pokémon encountered in the wild have a 10% chance of becoming one of several Ghost-type Pokémon in the event that they would otherwise not be Ghost-type.
• Phantump and Pumpkaboo can be found lurking in Peridot Forest. Each map contains one of the two. After an encounter, they will disappear and respawn after a week. This allows for a maximum of 5 encounters with each map for a total of 20 throughout the month.
• Specific sand castles in Citrivale Docks, Amaris City, and Ironis City will be revealed to be Sandygast. After an encounter, they will disappear and respawn after a week. This allows for a maximum of 5 encounters with each map for a total of 15 throughout the month.
• The power of Ghost- and Dark-type moves are increased by 30%
• Margot's outfit changes to a dress and hat based on Mismagius during the month.

Ghost-Type Pokémon Spawning

During the month of October, there is a 10% chance of the player encountering Ghost-type Pokémon rather than a Pokémon they would normally encounter if it is not already a Ghost-type. The way what Pokémon is encountered is determined as followed:

The game creates four slots. Two are filled by Duskull and Yamask. The other two are left blank. The game then uses the original Pokémon's type to attempt to fill in these two slots.

• Litwick if the Pokémon is Fire-type
• Frillish if the Pokémon is Water-type
• Drifloon if the Pokémon is Flying-type
• Golett if the Pokémon is Ground-type
• Gastly if the Pokémon is Poison-type
• Sableye if the Pokémon is Dark-type

Dual-types are taken into account. If the Pokémon is a single type, the remaining slot is filled by Shuppet. If the Pokémon is none of those types, the slots are filled up by Misdreavus and Shuppet. The Ghost-type Pokémon encountered is then randomly chosen from the four resulting options.

For instance, if the player would have normally encountered an Altaran Growlithe and this occured, they would instead encounter a Litwick, Frillish, Duskull, or Yamask.

There are a few exceptions to this:

• The starter Pokémon the player catches
• The Alolan Raticate found in Sidequest: Pest Extermination