Junit Clock

@Test
    public void testGetDeliveryDateEightDaysAndHoliday ()
    {

        new NonStrictExpectations( product )
        {
            {
                product.getDeliveryDays( 1, 1 );
                result = 8;

            }
        };

        Clock clock = Clock.fixed( Instant.parse( "2017-06-29T12:30:00.00Z" ), ZoneId.of( "UTC" ) );

        Date deliveryDate = product.getDeliveryDate( 1, 1, clock );

        Calendar cal = Calendar.getInstance();
        cal.setTime( deliveryDate );
        int day = cal.get( Calendar.DAY_OF_MONTH );

        Assert.assertEquals( 11, day );

    }


public Date getDeliveryDate ( final int contextId, final int quantity, Clock clock )
    {
        Date returnValue = null;
        int daysToAdd = quantity > 0 ? getDeliveryDays( contextId, quantity ) : getDeliveryDays( contextId );

        final DeliveryBlock block = DeliveryBlockManager.getInstance().getDeliveryBlock( getClientId(), contextId );


        LocalDateTime localDateTime = LocalDateTime.now(clock);
        if ( block != null && block.isValid( Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant()) ) )
        {
            daysToAdd = localDateTime.getHour() < DELIVERY_TIME_LAST_HOUR ? daysToAdd - 1 : daysToAdd;
        }

        if ( daysToAdd <= 0 )
        {
            returnValue = Date.from( getNextDate( localDateTime, block ).atZone( ZoneId.systemDefault() ).toInstant() );
        }
        else
        {
            LocalDateTime deliveryDate = Stream
                    .iterate( getNextDate( localDateTime, block ), t -> getNextDate( t, block ) ).limit( daysToAdd )
                    .reduce( ( a, b ) -> b ).orElse( getNextDate( LocalDateTime.now(), block ) );
            returnValue = Date.from( deliveryDate.atZone( ZoneId.systemDefault() ).toInstant() );
        }

        return returnValue;
    }