What does this policy mean for Remote's clients?

The policy (and the law) simply requires the parties to communicate and come to a (preferably) written agreement about how and when the employee will be required to respond. Ideally, this will be already in the employment agreement. If for whatever reason the working hours are not clearly defined, or they have changed since the employment agreement was executed, we would be happy to assist you in amending the agreement to state the working hours clearly.

See also: How to request changes to an employee's contract