[threeten-dev] Calendar.toZonedDateTime?

[roger riggs]

Should it be possible to convert any java.util.Calendar object to a 
ZonedDateTime?
The conversion works from an Instant and a TimeZone both found in Calendar.

The current placement of toZonedDateTime in GregorianCalendar does not allow
it to be used with some calendars, for example a Japanese Imperial Calendar
is not of type GregorianCalendar.

Could toZonedDateTime be moved up the Calendar?

Roger