When and where your finely crafted television programme is placed within the channel schedule has long been crucial to the show's success.

It’s the TV scheduler who makes these decisions. Drawing on audience research and channel strategy, they make sure each programme reaches its target audience as best as possible, balancing it against what rival channels may be broadcasting in the same time slot.

What exactly does a TV scheduler do, why are they important and how is scheduling changing in an on-demand age? Schedulers from BBC Three, Four and Dave tell us more.