What is one ISO standard date time format listed?

• A. YYYY-MM-DD HH:MM:SS
• B. YYYY-MM-DD
• C. YYYYMMDDTHHMMSS
• D. DD-MM-YYYY HH:MM:SS

Answer: (A)

ISO 8601 aims for a clear, unambiguous date and time presentation, using a consistent order and separators. The form that shows the four-digit year, two-digit month, two-digit day, followed by a space and then the two-digit hour, minute, and second (YYYY-MM-DD HH:MM:SS) matches the commonly taught extended representation of a combined date and time in ISO style. It clearly presents both date and time in a standard year-month-day sequence with standard separators, making it the best example among the options. The other formats either omit the time, use a non-ISO day-first order, or use a compact form that is valid but less representative of the typical ISO extended format.