As we have integrated schedule setting into backup wizard for a normal plan, the Exchange schedule setting is also added in normal Exchange backup wizard. Therefore you have to determine to the schedule settings if you want to run a schedule backup for your Exchange Server, just selecting the time point when you need the task running to make current task as an Exchange schedule backup. More about how to set the time points please refer to Schedule setting.
Since Exchange server always need to stay in working service, so we have remove one of the schedule setting "Based on Windows or Windows user login/logout".
Step-by-step tutorial: How to backup and restore MS Exchange Server?