Time Machines are inventions that are used to travel to any year, time or day. These machines are used by the characters to meet their future counterpart.
These machines take up a lot of energy according to Bulla. Although, these machines are more comfortable and durable for traveling. These machines can actually teleport pretty quickly.
Well like all time machines, these things are used to go to any time period that you desire. Although, time traveling can be dangerous because you can easily change the time period just by telling a brief piece of information, like what Jill did, however no danger has happened. If the machine gets damaged badly, then you will be stuck in your present time area that you're in. This is another example about the dangers of time traveling. Steve got strandad in the past after Bulla left with the time machine