Document why we set endTime to the current date initially
Document why we set endTime to the current date initially

Contributes to issue CURA-3161.

fieldOfView/Cura,Curahelper/Cura,hmflash/Cura,ynotstartups/Wanhao,hmflash/Cura,Curahelper/Cura,fieldOfView/Cura,ynotstartups/Wanhao