Be aware, you can get locked out of your charity’s account if you don’t enter it correctly.

You can ignore this pop-up message and dismiss it for a while, but eventually it does seem to stick and not let you close the box without this information.

When you add a date, do NOT make it younger than 13 when X started in 2006, otherwise your account will get locked/closed for being underage when X first began.

I’m seeing reports of it being very difficult/impossible for people to get their charity/corporate accounts unlocked and some having to start new accounts again. Or when their account is reopened, not seeing any tweets earlier than their prior age 13 date.

Also X customer support is minimal to non-existent, especially if you have a free account. Mind you, it’s a whole other issue as to whether you should quit X generally, which I’ve written about lately on here.

WHAT DATE TO PUT?

Suggestions include make it the date your organisation was incorporated, or a team member’s date of birth, but just be aware of the above issue.
Best advice is is to only use someone who turned 13 well before Twitter was founded in 2006 (i.e. born before 1993), and make a note of it centrally.