Using a map is done via the ACE interact menu by holding your ACE interact key (Windows key by default) and looking at the option you'd like. The map allows you to:
Sleeping will skip the amount of hours you choose. You will NOT receive taxes during this skipped time, however are welcome to skip time to just before a tax payment is due (6am, midday, 6pm and midnight).
Not really required much these days, but however if your cash/wanted status disappears you can reset it with this option.