It’s pretty speedy, but it does depend on where you are located in the US.
Generally, orders going to the east coast will arrive quicker than those on the west coast (there’s a lot of ground to cover across the pond!), and from the point of dispatch, orders tend to be delivered within 7 working days.
DHL deliver parcels from Monday to Friday between 8am and 6pm. If you are not at home when the courier tries to deliver your parcel, you will find a missed delivery note in your mailbox. You can also manage your shipment on DHL's On Demand Delivery site, which has an array of in-flight options.