Notes:

For example, take this code that adds two months to today's date.

The standard library needs to convert the date to a julian date in the constructor, convert it back to a civil date to add the months, add two months to the civil date to get a new civil date, and convert that back to a julian date in order to store it.

With home_run, the initial storage is done directly with the civil date, and the addition of months uses the civil date, so no conversion to or from a julian date is ever done.