Deferred Pension - when to start claiming

Can someone please confirm that this calculation is correct as my client has had various dates given to her by phone, even from the same DWP adviser, so she is reluctant to accept what is said. 

This is what she wrote: 
“Pension is paid in retrospect.
My state pension entitlement is from 6 September 2013
I would be paid on a Tuesday (determined by NI number)
First full week would be Wednesday 11 September to Tuesday 17 September 2013.  (see example on DWP website for how this is calculated)
I would not be paid from 6 - 11 September because it is not a full week.  Has to be a full week.

I did want to defer for 105 weeks, ie 21 x 5 week periods. 
105 weeks from Wednesday 11 September 2013 is Tuesday 15 September 2015.”

The DWP site does seem to suggest that the deferral is calculated in 5 week periods, (see https://www.gov.uk/deferring-state-pension) but I thought the calculation would be 0.2% per week.  Should she claim from a Wednesday to ensure she has the maximum number of full days and doesn’t lose out, albeit by a small amount of actual cash?