Question

How can I learn how many days passed from a spesific date? Which package i need to use and how?

Answer 1

EDIT My previous answer was only valid within a year.

You can use the milliseconds difference like this:

Date date1 = // some date
Date date2 = // some other date
long difference = date2.getTime() - date1.getTime();
long differenceDays = difference / (1000 * 60 * 60 * 24);

Basically the same as timbooo answered, just a shorter way.