insert ProblemsMoreThan7BusinessDays
(
    businessdays
,   number
)
select
    number
,   sum( businessday ) -- or count(*)
  from OpenProblemtimeDiffTable op
 inner join CalendarInformation ci on op.problem_new >= ci.[date]
   and op.[now] <= ci.[date]
   and ci.businessday = 1
 group by
    problem_number

select p.ProblemNow
      ,p.Now
      ,sum(c.BusinessDay) as BusinessDays
from dbo.Problems as p
    join dbo.calendar as c
        on c.CalendarDate between p.ProblemNow and p.Now
group by p.ProblemNow
        ,p.Now