For a date set coin collection, the collector selects one specific coin and collects a sample from each year the coin was produced. Mint marks are not taken into consideration.
A major advantage of collecting coins by date is that it is acceptable to use less expensive coins to complete the set. The prices of collectible coins sometimes vary significantly due to availability. It is possible to purchase a common coin in very good condition for far less than a well-worn rare coin. After finishing a date set for one type of coin, some collectors go on to compile complete date sets for all values of coins from a selected country.