Why is my timer stopping at 4am?

[Save_me_ a_few_Bob]

Boiler is an ideal esprit eco 24


The mechanical timer will stop automatically, for e.g. at 11pm i will set it for 7am the next day but it will freeze/stop at 4am

When i turn it back to the correct time it will start working again but only for a few hours

What is the issue?

 

[terryplumb]

Commonly known as goosed !

 

[ianmcd]

new timer required the cog teeth are worn