extract day from Date

Question

I receive a timestamp from a SOAP service in milliseconds. So I do this:

Date date = new Date( mar.getEventDate() );

How can I extract the day

Answer 1

Given the Date constructor used in the question

Date date = new Date(mar.getEventDate());

The method mar.getEventDate() returns a long that represent the specified number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT.

Java 8 and later

In Java 8, you can extract the day of the month from this value, assuming UTC, with

LocalDateTime.ofEpochSecond(mar.getEventDate(),0,ZoneOffset.UTC).getDayOfMonth();

Note also that the answer given by cletus assume that mar.getEventDate() returns a Date object which is not the case in the question.