When creating a Schedule, you first need to designate the type of the Schedule, whether it will be a “Loose” or a “Strict” Schedule by clicking on the “Loose” checkbox. The main difference between the “Loose” and “Strict” Schedule, is that in the “Strict” Schedule you have to specify the Scan time for each Checkpoint individually. For the “Loose” Schedule variant you just set the Check Time Range for the beginning and the ending of the Schedule only.
For more info related to the creation of Schedules, visit the Web Application guide (Routes).