This function is especially helpful if one wants to show a completed sections only as one entry in the Gantt-chart

collapse_complete_sections(dt)

Arguments

dt

time lines processed by calculate_time_lines

Value

dt but all sections that do not contain an 'uncompleted' task are collapsed to one entry. Start and end time for the collapsed entry are the minimum and maximum start and end times of the single tasks and deadline is set to the minimum deadline (if available).