Best Format for Ranges on a Form: Vertical or Horizontal?

In our system, we have long forms used for data entry. Our entry fields, checkbox controls, and combo boxes are always listed down the left side of the screen in one column.

Our persona deals with these long forms and data entry all day; therefore, they are used to seeing one column of data entry.

In the example below, our persona wants to run a report for any check dates that fall between 7/1/16 and 6/30/17.

Should date range fields be vertical with two labels or horizontal with one label?

A or B?