Logic would say that if someone can care for a child for 1 hour 59 minutes at their home, then could the extra time not be absorbed by doing something else, such as going to the park, shops, library.
Care Standards Act 2000
"79A (7) This Part does not apply in relation to a person who acts as a child minder, or provides day care on any premises, unless the period, or the total of the periods, in any day which he spends looking after children or (as the case may be) during which the children are looked after on the premises exceeds two hours."
Which I take to mean, care provided ON THE PREMISES counts towards the time limit, but care provided off the premises does not.
Cross Reference with HMI 2601a - See paragraph 16 for definition of a childminder.
Nicks Disclaimer: I am not a lawyer... so this is my personal view and not a legal view or legal advise. Please seek professional advice if you require it.