What is the Buddhist calendar today?

Calculation method of Buddhist calendar:

Add the years of Buddha Sakyamuni's nirvana to today's years.

(for example: 543 +20 15+1 year =2559),

Every year, one year is added from the birth date of Sakyamuni Buddha, and so on.

How to calculate the Buddhist calendar:

That is, Sakyamuni Buddha was born in 623 BC MINUS 80 years of Buddha's life, that is, 543 BC was the year of Sakyamuni Buddha's nirvana (Buddha's nirvana was in 543 BC).