int hour = mdt.hourOfDay().get() + hours;
activity.setEnd(new Time(mdt.copy().hourOfDay().set(hour)));
activity.setProject(Ref.create(projects.get(random.nextInt(projects.size()))));
for (int i = 0; i < TAGS_PER_ACTIVITY; i++)
{
Tag tag = tagKeys.get(random.nextInt(tagKeys.size()));
activity.addTag(Key.create(tag));
}
activities.add(activity);
mdt.hourOfDay().add(hours);
}