How to change Gen9 trainer birthday?

[dawnsqrl]

Is there a reliable way of modifying / resetting the trainer birth date and month in SV? I don’t think they can be found anywhere in the Trainer Info tab. Strangely, barely anyone has talked about this online, so I'm not sure if I have missed it somewhere. I'm using v20250609.

As a workaround, I looked into PKHeX.Core/Saves/Access/SaveBlockAccessor9SV.cs and was able to dig up

*Bool KSelectedBirthday
*Bool KIsBirthdayToday
*Int32 WSYS_BIRTHDAY_EVENT_TIME

in the Block Data editor, but

• WSYS_BIRTHDAY_EVENT_TIME stores the date value as Unix timestamp, which needs conversion before changing or checking every time.
• If the birthday has already been set in-game, it appears that resetting WSYS_BIRTHDAY_EVENT_TIME to 0 and changing KSelectedBirthday and KIsBirthdayToday back to false still won't unlock the ability to re-choose a birthday in game.

So is there an officially supported way of doing these in PKHeX? The block-editing method feels quite cumbersome, and there are still some low-level details that I couldn't figure out.

Thanks for the help!

[kwsch]

Standard research practices would apply, where you would take a "new" save file that hasn't yet done it, then set the birthday, then do a before/after comparison and whittle down the list of changed blocks/flags to see what actually determines elligibility.

[dawnsqrl]

After some further diffing I was able to figure out what exactly happens with birthday events.

When a birthday is set:

• *Bool KSelectedBirthday: false → true
• *Object MyStatus
  • BirthDay: 0 → birth date (1-31)
  • BirthMonth: 0 → birth month (1-12)

When birthday actually comes:

• *Bool KIsBirthdayToday: false → true
• *Int32 WSYS_BIRTHDAY_EVENT_TIME: 0 → Unix timestamp of this year's birthday at 0:00:00

Since PKHeX does not have a built-in field for birthday, the easiest and most reliable way is to undo birthday selection by reverting all 4 data blocks, then set it in-game again.

[Lusamine]

Since PKHeX does not have a built-in field for birthday

Isn't the BirthDay and BirthMonth in MyStatus the built-in editable field for your birthdate? Does it not work to change it with KSelectedBirthday = true and have the game accept it next time that date rolls around?

[dawnsqrl]

Sorry for the confusion – by "built-in editable field" I originally expected that there would be a field in the Trainer Info dialog that exposes the birthday directly, so I don't need to dig into the Block Data editor and search for potentially relevant keys myself. I didn't see many people having difficulty about changing their birthdays before, so there wasn't much to reference and I thought I had missed a very obvious field somewhere, hence the original question.

I think it's very likely that changing MyStatus will also work as intended.

Since a birthday field does not exist in Trainer Info yet, I'd like to try adding it in. Maybe I can figure that out for Gen8 SwSh as well.

[Lusamine]

I think you misunderstand. Some of the blocks in the block editor are already defined and that's where you were supposed to edit it. Likewise, blocks that are integers or booleans can be edited that way. Yes, editing it there should change the value in the save file. The original suggestion to diff the saves was assuming you had looked and the existing fields were insufficient. You do not need to add another editor elsewhere for it to work.

If you weren't aware, the block editor has a feature where you can enter a word in the list of keys and it will bring up all of the keys that contain that word in the name, so you wouldn't need to visually inspect for them.

[dawnsqrl]

Thank you for the clarification! That clears up my confusion. In that case I will not try to add another field somewhere else.

For the block editor – I actually didn't realize that pressing enter on the Block Key will perform a keyword search, even if the autocomplete list is empty. I always thought it can only filter entries based on the prefix I input. Thanks for the tip!