Field order for slide mode
This is a i18n option! i18n options can not be set directly on a per-instance basis, you must include the "override" directive, and properly camel case the new name - (i.e. overrideSlideFieldOrder). For more information, please take a look at the Localizing Datebox section.
If you want a slider that does date and time, try something like:
Data Type Expected
array('y', 'm', 'd']
Option is Dynamic Post Initialization