Work Item Pre wait delay

Hi,

I want to know when Collection begin calculation of pre wait delay assigned to workitem, is it when strategy is assigned to customer or when Workflow program is runned

Example : I have work Item (print dunning letter) with pre wait delai 5 days

On the first day of the month I assigned this work item to customer (using strategy management program)

I runned Workflow programm 3 days after (fourth day of the month)

Dunning letter will be printed on the 6th of the month (1+5), or 9th (4+5)

Thanks

Mehdi