Puzzles are often one of several standard sizes. For example, many weekday newspaper puzzles (such as the American "New York Times" crossword puzzle) are 15×15 squares, while weekend puzzles may be 21×21, 23×23, or 25×25. The "New York Times" puzzles also set a common pattern for American crosswords by increasing in difficulty throughout the week: their Monday puzzles are the easiest and the puzzles get harder each day until Saturday. Their larger Sunday puzzle is about the same level of difficulty as a weekday-size Thursday puzzle. This has led U.S. solvers to use the day of the week as a shorthand when describing how hard a puzzle is: e.g. an easy puzzle may be referred to as a "Monday" or a "Tuesday", a medium-difficulty puzzle as a "Wednesday", and a truly difficult puzzle as a "Saturday". One of the smallest crosswords in general distribution is a 4×4 crossword compiled daily by John Wilmes, distributed online by "USA Today" as "QuickCross" and by Universal Uclick as "PlayFour".