The vast majority of high-end mechanical grandfather clocks, whether they have cable driven movements or the chain driven movement type, have 8 day movements. This means the movements, when fully wound, will run for eight days. This is true for Howard Miller Grandfather Clocks, Hermle Floor Clocks, the Ridgeway Grandfather Clock Collection, Bulova Grandfather Clocks, and the made-to-order Kieninger Grandfather Clock Collection.