Blue bloods season 14 episode 1 on sky TV, on TV it is 1 hour but on demand is 48 minutes. Do this it takes away all of the adverts, when watching on demand

Yes, that's correct! The discrepancy in duration between live TV and on-demand services often occurs because live broadcasts typically include commercial breaks, which are not present in on-demand versions. When you watch "Blue Bloods" Season 14, Episode 1 on-demand, you’re seeing a version that is edited to remove those advertisements, resulting in a shorter overall runtime—as you mentioned, about 48 minutes compared to the 1 hour aired on live TV. This is a common practice in many streaming services and on-demand platforms.