TimeCop::freezeDuring static method that freezes time during the execution of the passed lambda (Runnable). Idea stolen from my days as a ruby dev https://github.com/travisjeffery/timecop

TimeCop.java

package my.awesome.namespace;

import org.joda.time.DateTime;
import org.joda.time.DateTimeUtils;

public class TimeCop {
  public static void freezeDuring(Runnable block) {
    DateTimeUtils.setCurrentMillisFixed(DateTime.now().getMillis());

    block.run();

    DateTimeUtils.setCurrentMillisSystem();
  };
}

// usage example
TimeUnit defaultUnit = TimeUnit.HOURS;
int defaultInterval = 1;

TimeCop.freezeDuring(() -> {
  myDate = new Date(System.currentTimeMillis() + defaultUnit.toMillis(defaultInterval));

  ClassUnderTest.someMethodThatTriggersADateCreationInAPrivateDelegateMethod();
});