What is the date inscribed in the exterior of Wuthering Heights?

The date inscribed on the exterior of Heathcliff's home was the year 1500.

Before passing the threshold, I paused to admire a quantity of grotesque carving lavished over the front, and especially about the principal door; above which, among a wilderness of crumbling griffins and shameless little boys, I detected the date '1500,' and the name 'Hareton Earnshaw.'

the date which is inscribed on the exterior Heathcliff's home was the year 1500.