In Cantonese, you can use 遲 to indicate someone is late (e.g., not punctual) or the time is late (e.g., past midnight so all restaurants are closed).
However, it seems like Mandarin speakers use 晚 in place of 遲 most of the time.
What are the Mandarin guidelines for using 遲 vs. 晚? Should you just always use 晚?