Why is there a "63" in the date February 29th, 1988?

[Julian1203]

 

[Toritoribe]

Japanese era name - Wikipedia, the free encyclopedia
Shōwa 63 = 1988

 

[Sultan]

View attachment 22511

In Japan they have like their own chronology system. Each emperor has his motto, the era of his emperorship is named after the motto and years are counted like 63th year of X era.