The Sea of Stars is unusual in that all of the lands upon it have the same seasons, indeed the same length of day, as the Sun is allowed out for longer times during the summer and shorter periods in the winter. As the Empress likes summer best, it lasts for four months, rather than the three for each of the other three seasons, and in the middle of Summer on the day with the most daylight, her birthday is celebrated (or at least recognized) across the Empire.
The tradition has evolved to have a huge party in the Capital starting at dawn. The Empress mingles with her people and gives out gifts and recognition to the Imperial bureaucracy and military and, occasionally, to one or more of the Draconic Houses. In the later afternoon, she ventures out to visit other celebrations, bringing stories, entertainments and gifts. The appearance of the Empress at one of the distant celebrations is a great honor . . . and a terrifying experience. There are rumors, never proven, that one insult will lead to the wrath of the Empress and the extermination of all who participated. But no one has visited such a place, or even met someone who has, but always a cousin who met someone who knew a traveler who found such a ruin.
Feasts, contests and fireworks after the Sun returns to his prison are the traditional entertainments and Imperial duties and taxes are suspended for the day, the Empress wishes everyone to enjoy the day, at least, so her proclamations say.
While the Empress’ Birthday is celebrated, her age is never discussed. (Though it is believed to be well over two millennia possibly as much as three and a half.)