Downtime is when a cloud service is inaccessible to users on the internet for a determined period. The best answer to the question would be “never”. However, even the biggest and reliable cloud providers experience occasional downtime. This could have a disruptive impact on the business, the best option is to choose a provider with a history of minimal downtime. The SLA(Service Level Agreement) needs to provide this information and include incident response procedures, so that the business is updated on when the service will be back online.