Contacted Chase to ask about definition of "overnight" for Sapphire Preferred benefit. They referred me to the benefit administrator. The customer service representative was unsure, so they had to pull in someone from claims to get an answer.

The definition for overnight is 3 hours at night time. What this means is that if your flight at night is delayed 3+ hours (ie. 12:55am departure delayed to 5:35am) at night, you are eligible and can get up to $500 reimbursed for meals, hotel, etc.