Meaning of "Work planned for the first days of the Sprint by the Development Team is decomposed by the end of this meeting, often to units of one day or less. "

Hi All,

I would like to bring this topic up again as in our tribe we are facing this questions:

In the Scrum guide is mentioned "Work planned for the first days of the Sprint by the Development Team is decomposed by the end of this meeting, often to units of one day or less". 

Could anyone help me to understand this sentence correctly? does it mean the team should decompose (create sub-tasks) that are enough for first days of the sprint?