Birthday Medallions

While each kingdom and even individual families or groups have their own personal birthday traditions whether it's visiting a favorite location, dinner at your favorite restaurant, a picnic under the Great Tree in Rhodis, drinking around the empire in UMLOT, etc. the one tradition they all share together is the Birthday Medallion.
A humble tradition that was created as a way to give every citizen of the empire a chance to have their birthday celebrated just like the emperor's was each year. The medallion is worn usually over the heart, but can be placed on a hat, on the cross strap of a bag, almost anywhere though the more visible it is the easier it is for people to spot it and recognize you accordingly.

Execution

On the morning of one's birth they head down to city hall and check in with their local officials to confirm it's their birthday. They can than submit how they'd like to have their medallion personalized, and the officials will get it ready for them. From there they attach the medallion to their clothing and wear it around for the day.
From there the medallion does the rest, most people you cross paths with will wish you a happy birthday, even total strangers, extending a small gesture of polite kindness. In some businesses you'll find they take that kindness just a little bit further, some restaurants will gift you an appetizer or a specialty dessert, some stores will toss in a discount or a small trinket of some sort.

Components and tools

Birthday Medallions (the design varies from Kingdom to Kingdom) and a simple set of engraving tools

Participants

Medallions are presented to the celebrant by officials at their local city hall and personalized how they wish, typically with their name or a favored nickname (but anything within reason and good taste).

Observance

As the name implies, the birthday medallion tradition is an annual occurrence falling on each citizen's recorded day of birth.