On this page you’ll find a clear, concise answer on the time/age at which you need to replace the timing belt on your 2004 Alfa Romeo 147 with the 1.9 JTD 16V engine.
At launch, your 2004 Alfa Romeo 147 (1.9 JTD 16V) had a recommended timing belt replacement time of 5 Years.
However, owing to failures occurring earlier than this official replacement timeframe, the recommended timing belt replacement time/age for your 2004 Alfa Romeo 147 (1.9 JTD 16V) is 4 years recommended, 5 maximum.
Use 4 years recommended, 5 maximum and not 5 Years, unless you want to risk premature timing belt failure and expensive engine damage.