Every parent should be involved in the child’s life (subsection 1(2A) of the Children Act 1989)
On any application for a Specific Issue Order (or any section 8 order), the court must presume that each parent being involved in the child’s life will be good for the child’s welfare, according to subsection 1(2A) —
- (2A) A court, in the circumstances mentioned in subsection (4)(a) or (7), is as respects each parent within subsection (6)(a) to presume, unless the contrary is shown, that involvement of that parent in the life of the child concerned will further the child's welfare.
- (2B) In subsection (2A) “involvement” means involvement of some kind, either direct or indirect, but not any particular division of a child's time.
A “presumption 
” means that the court must take a fact as true, unless someone can show evidence that it’s not true — which is called “rebutting” the presumption. In other words, it puts the burden of proof on the person who wants to show that the presumption is wrong — which for the presumption in subsection 1(2A) means proving that a parent being involved in the child’s life isn’t in the child’s best interests.
The presumption applies to parents whether or not they have parental responsibility, so long as there’s no evidence that the parent being involved will put the child at risk of harm.
However the type of involvement that will benefit a child is still up to the court — as made clear by the definition of “involvement”. The court doesn’t have to presume that every parent being given a “particular division of a child’s time” (e.g. every Saturday afternoon) is in the child’s best interests, or even that direct contact with the child is in the child’s best interests. It merely has to presume that some sort of contact with each parent (at an appropriate level) is good for the child.