I’ve created a PDF document that shows my interpretation of how 15 USC 260-164 would look with HR 1556 applied.
15 USC 260ff is the current United States Code that defines “Standard Time”, and also contains the provisions for Daylight Saving Time.
HR 1556 basically would remove 15 USC 260a, the section dealing with Daylight Waving Time, and then redefine the various time zones to be one hour earlier than the current defined time, year-round.
View the text of 15 USC 260-264, the text of HR 1556, and my interpretation of the result.