This simple Registry tweak will let you enable the old classic Windows 8.1/7 like Clock and Calendar in Windows 10 so that you can use it, as you had been using it in the older version of Windows.

According to Richard Conn Henry's calendar, eight months would each have 30 days. Every third month would have 31 days. Every so often, to account for the leftover time, a whole extra week would ...

The clock doesn’t have a 50 year run time because the batteries it’s designed to run on will self discharge in about half that. I’ve no idea what kind of battery could really last 50 years.