I have posted two images/screenshots (see below) which give an idea about this.
According to Haynes manual, it's at 72 months (6 years) and
According to the Skoda Servicing chart, it's at 60 months (5 years) or 50K miles (whichever comes first)
In the Haynes manual, they say "it is strongly recommended that the interval be reduced as suggested, especially for vehicles used intensively, e.g. short journeys or stop-start driving. This explains why it is better to change the timing belt at 50K miles rather than waiting 72 months, because, I believe the Octavia MK-III cars many of you have are equipped with automatic stop-start when moving in slow traffic or near colour/traffic lights. It is fair to assume that each stop-start would add additional stress on the timing belt compared to a scenario where you drive on the motorway (constant momentum/torque in the engine).
I couldn't trust Marshal Skoda Northampton and the expertise of their mechanics even though they gave the service history of the car. Because they had missed or ignored the manufacturer's recommendations to perform certain services/maintenance work at the right time/mileage before they sold the car to me. Instead, they have postponed them until the next year when I come to get the car serviced under the service plan they sold to me.
Ignoring changing the brake fluid, DSG fluid and Timing + Water pump as per their own service/maintenance chart is unacceptable. They didn't at least recommend that to me at the time of the sale (at 54000 miles), maybe thinking that I would ask for a discount for all the maintenance work due at that mileage (Please refer to the second image in Green).
Then in the next year when I went to claim the first service of the service plan I bought from them, their dealership garage tried to rip me off saying that I must get these done immediately and gave me a huge quotation. Those prices were more than double the prices given in this Green colour chart, but I had no idea about the actual prices then. Without thinking much, I asked them to change the brake fluid and DSG fluid and I paid for those. Since they told me I would have to leave the car at the garage for 2 more days to change the timing belt, I drove off that day with the intention of returning to their garage a few days later to get the timing belt changed. That's when I started to study the vehicle and service/maintenance intervals! Thanks to the people on this forum, I learnt how Marshal Skoda Dealership & Garage in Northampton deceive people!! What I paid so far was double the price compared to another Authorised VW Garage in Milton Keynes. Even for the timing belt change, they quoted me £900+. So, I got it done at a local garage (with very honest, non-pushy people) for about £500.
The Timing Belt + Water Pump Kit was Gates Powergrip whereas Marshal Skoda Dealership Garage claims that they use OEM parts. But I do not know if I could actually trust Marshal Skoda Dealership and the level of attention their mechanics pay. They sold me the car at 54000 miles...according to their own service/maintenance chart, the Brake Fluid, DGS Fluid and Timing Belt should have been charged at 50000 miles. But they didn't even recommend that I should immediately get those done, probably just because they thought I would ask for a discount.