The various elements that contribute to the production of magazines vary wildly. Core elements such as publishing schedules, formats and target audiences are seemingly infinitely variable. Typically, magazines which focus primarily on current events, such as Newsweek or Entertainment Weekly, are published weekly or biweekly. Magazines with a focus on specific interests, such as Life Positive and Cat Fancy, may be published less frequently, such as monthly, bimonthly or quarterly. A magazine will usually have a date on the cover which often is later than the date it is actually published. Current magazines are generally available at bookstores and newsstands, while subscribers can receive them in the mail. Many magazines also offer a 'back issue' service for previously published editions.