Can Prelim deductions occur under NEC 3 Option B

Summary Notes:

  1. Contractor start date was 8 weeks ago
  2. Contractor didn’t attend site for 2 weeks after their start date
  3. Contractor has worked 6 weeks onsite in total

is this contractor entitled to claim 8 weeks prelims from the start of his contract or can the client make deductions and pay only 6 weeks he was actually onsite.