SELECT
DATEDIFF(day, COALESCE(date0,dateStart),date1),
DATEDIFF(day, COALESCE(date1,date0,dateStart),date2),
DATEDIFF(day, COALESCE(date2,date1,date0,dateStart),date3),
DATEDIFF(day, COALESCE(date3,date2,date1,date0,dateStart),date4),
DATEDIFF(day, COALESCE(date4,date3,date2,date1,date0,dateStart),date5),
DATEDIFF(day, COALESCE(date5,date4,date3,date2,date1,date0,dateStart),date6),
DATEDIFF(day, COALESCE(date6,date5,date4,date3,date2,date1,date0,dateStart),date7)
FROM temp