The response time displayed on your freelancer profile is calculated based on the average time it takes you to respond to the first email (via the Malt Inbox) received by a client with a new project proposal from the time that message first landed in your inbox.
The good news: We calculate "response time" on a rolling basis. We know that sometimes you can't immediately respond to all of the messages you receive—and we would never want to penalize you forever for that one message that took you exceptionally longer to respond to.
So, if you're typically great at responding within an hour, that one time when it took you a full day to respond won't negatively impact your displayed "response time" in the long run.
However, please keep in mind that "response time" does influence your ranking in search results, so it's important to do your best to respond to the messages you receive from potential new clients as quickly as possible.