Hi,
You could do it using laravel's task scheduling and Carbon (for working with dates). https://laravel.com/docs/8.x/scheduling
For example, you create a job to send Happy Birthday emails. Then in the job, with the help of Carbon, you define the logic that on each year, on users b-day they get an email. All that it's left is creating a command and adding it to the comand Kernel.php.
PS: You'll also have to add an entry inside the crontab on your server as per the documentation.