Date.dayDiff()
The Date.dayDiff() API returns the difference between two dates in terms of days.
Examples
pjs.define("date", { type: 'date', initValue: '2017-01-01'})
pjs.define("date1", { type: 'date', initValue: '2017-01-30'});
pjs.define("diff", { type: 'integer'} );
diff = Date.dayDiff(date1,date);
return diff;
// 29