Question

The idea is to have a reminder for my birthdays Notion page. I have everything, but I would like to have a reminder the same day of the birthday and repeat that every year.

A formula may do the trick.

One column with a date (the birthday) and another one with a reminder formula. Check the date and add a reminder with that date using @reminder + the date.

Is something like that possible?

Answer 1

The problem with formulas is that they only work in databases. @reminder is not something the database recognizes inside formula properties. In addition unlike date properties, formula properties do not have the option to set reminders.
A workaround is to create a birthday calendar using formulas to get their current age: Notion Birthday calendar and then use a relational database like your daily log to remind yourself of a persons birthday. Only @mentions or date field properties at the moment have the ability to give you reminders. In addition the only way to make something recurring in a calendar view database is to duplicate the page.