Since version 4.0.1, Apache POI requires Java 8. In that Java version, the new date/time API was introduced which is both easier to use and less error prone than the old (and flawed) API consisting of java.util.Date etc.

Client code that uses the new LocalDate and LocalDateTime classes nonetheless has to convert dates to the now somewhat obsolete old classes when dealing with POI. To leverage this, support for LocalDate/LocalDateTime should be added to POI, namely the Cell interface and DateUtil class.

Since the old java.util.Date based API is still used by a lot of client code, support should be added in a backwards compatible way.

I volunteer to add this support, as well as doing some cleanup of the date/time handling.