Just keep it simple and use Java please. There are examples in the doc: https://github.com/intuit/karate#java-interop
If it is too troubling, write JS utility functions.
* def toDate =
"""
function(s) {
var SimpleDateFormat = Java.type('java.text.SimpleDateFormat');
var sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
return sdf.parse(s)
}
"""
* def raw = "2018-10-19T11:53:39.8795965Z"
* def date = toDate(raw)
* print date.day, date.month, date.year
Just look at the API for java.util.Date
and you have all of that now.