20 days plus 8 days statutory holidays... four weeks elective and 8 days stat. so it should just be exclusive of bank hols.
The overtime section seems a little like you are saying that overtime will be compulsory when it is available, I'm not sure you can do that.
the wording of section 19.2, (c) is a little odd, it sounds almost like you are asking them to agree not to work for another company doing the same job?
people change jobs but they less often change roles, its like you are saying you are not allowed to work for a competitor for 6 months after you leave the company, hardly fair.
but its a damn good template overall and only needs a few tweeks to be useable. thanks for sharing.