What is the ruling on dedicating a day to celebrate orphans?

There is no harm in designating a specific day for an activity or awareness campaign about the importance of caring for orphans and being kind to them, provided it does not involve anything Islamically forbidden. It is sufficient to conduct media awareness campaigns and hold lectures to encourage people to be kind to them, as evidenced by Ibn Mas'ud's dedication of one day a week to remind and admonish people.