Three real days to cover missed rent
Land and office leases now end for unpaid rent only after three full real-world days of arrears, instead of two game days — which was about six hours.
If a lease fell behind on rent, it was terminated after two game days of arrears. Game days are much shorter than real ones: at the world's current speed that was roughly six real hours. You could lose a site overnight without ever seeing the warning — and every time the world speed was raised, that window quietly got shorter.
The grace period is now three full real-world days, for both land rentals and office space. It is measured in real time on purpose, so it no longer changes when the world's clock speed does.
Nothing else about the lease changes: rent still accrues continuously, paying clears the arrears immediately, and the breach penalties on your agreement are unchanged. This only affects how long you have to put it right.