30 hour..? 8 day..?

If your clock has a '30 hour' movement, what does this mean?

Typically a 30 hour movement will keep your clock 'ticking' for 24-30 hours, at which point it will need winding. This may be with a key, which simply winds a steel mainspring into a barrel, or by pulling chains which have weights attached. 

Does a 30 hour movement mean it strikes? Not necessarily. Some 30 hours will strike (on the hour) whilst others may be a 30 hour timepiece movement only.

So what about an '8 day' movement? It runs for 8 days? Yes, and in years gone by it would be a weekly ritual to wind all the household's clocks at a particular time, before church on a Sunday for example. Again, this may be with a key, or using the weights.

An 8 day movement is used for striking, chiming or timepiece models.

Where would you find these movements? A Longcase/Grandfather clock (https://clockcorner.co.uk/collections/grandfather-clocks)would have either of the above, as would a Vienna wall clock (https://clockcorner.co.uk/collections/wall-clocks) Mantle clock (https://clockcorner.co.uk/collections/mantel-clocks) Grandmother or Grandaughter, each with either an hourly strike, or a chime at every quarter, depending on which of the two movements is used.