The existing "Use Kerbin Time" button uses the built in 'kerbin time', which appears to always be 6 solar hours.

• Add a custom DateTimeFormatter to return time for the "homeworld" - useful if the day length has been modified by a mod like Kopernicus
• Add a setting to override the built in date time formatter with the custom one (will default to off, since Kerbin's day is 6 hours in stock)