ENG> SPA quad-centennial rule?

[Antonio de Torre]

Hello, somebody can tell me what is the meaning of "quad-centennial rule" in
next context? If translated into Spanish, that would be great!

* Manage the leap year occurring in the year 2000, following the
quad-centennial rule.

It is within a text about compliance with Year 2000


Thank you very much
Cheers
Toni
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