Z00 Codes and delivery hours

Yes has to be within the hours bracket but you dont necessarily have to deliver all of the hours it has to be based on the planned hours i.e. on a scheme of work

Ooh, in years gone by, I had issues with bank holidays that we'd forgotten to take out of the hours...

As with all the counting hours things, I'd say there needs to have been some attempt to run the class (snow days/unavoidbale illness of tutor etc notwithstanding).  That's different from how many hours the learner actually attends, of course, which isn't at all important.

But, to answer the question, yes, 22 hours is perfectly acceptable.