The cam belt in a Fiesta LX 1.2 is not a part that needs to be changed at any certain time. It should be inspected every 100,000 miles and changed only if it shows signs of wear or breaks.
HOW MANY MILES BEFORE CHANGING TIMING BELT
30.000 - 40.000
80.thousands miles
120,000 miles , inspect and replace if necessary ( but I see another person has answered that their belt broke at 110,000 miles )
100,000
36,000 miles
90,000 miles
Every 100,000 k miles
10 years or 100,000 miles
120000 miles for first change
Ford recommends changing it at 150000 miles or 10 years. However, this is wait too much. It is usually recommended by users and mechanics to change it at 75000 miles. A broken belt means a new engine.
It is recommended at 90000 miles before major problems result from not changing it