Final answer:
In block formatted business or personal-business letters, hit the enter key once after writing the date to create a single blank line before the next section of the letter.
Step-by-step explanation:
In a business or personal-business letter following the block formatting style, after typing the date, you should hit the enter key once to create a single blank line.
This spacing rule is part of proper letter formatting and applies whether you're writing to someone in the United States, with the date formatted as January 1, 2010, or to someone in Europe, with the date formatted as 1 January 2010.
Remember to choose a font like size 12 Times New Roman or Arial for good readability and ensure that your letter is single spaced, with double spacing between paragraphs. No indentation is needed at the beginning of each paragraph.