Context: To unambiguously specify the date, dual dating or Old Style (O.S.) and New Style (N.S.) are sometimes used with dates. Dual dating uses two consecutive years because of differences in the starting date of the year, or includes both the Julian and Gregorian dates. Old Style and New Style (N.S.) indicate either whether the start of the Julian year has been adjusted to start on 1 January (N.S.) even though documents written at the time use a different start of year (O.S.), or whether a date conforms to the Julian calendar (O.S.) rather than the Gregorian (N.S.).

Question: What does duel dating use to show the date?
Answer: two consecutive years

Question: What is the Old Style date mean?
Answer: Julian calendar

Question: What is N.S. stand for?
Answer: New Style

Question: What are New Style dates?
Answer: Gregorian

Question: Why use two consecutive year dates?
Answer: starting date of the year

Question: What is used with dates to determine whether a date is correct or not?
Answer: Unanswerable

Question: What uses two different dates because of a difference in the ending date of the year?
Answer: Unanswerable

Question: Which system indicates that the Gregorian year has been adjusted to start on January 1?
Answer: Unanswerable

Question: Which system indicates that the date that the Julian date has been adjusted for length?
Answer: Unanswerable