0th

0th or zeroth is an ordinal for the number zero sometimes used under zero-based numbering, and may refer to:

• 0th grade, another name for kindergarten
• 0th dimension
• 0th element of an array data structure in computer science
• 0th United States Congress, also called the Congress of the Confederation
• January 0 or January 0th, an alternate name for December 31
• The zeroth law of thermodynamics
• Zeroth-order logic
• The Zeroth Law, an addition to Isaac Asimov's Three Laws of Robotics
• Zeroth order approximation; see Orders of approximation
• Zeroth, the fastest demo or highest score on a level or episode in N (video game)
• Zeroth, deep learning software for mobile devices

Distinguish from

• Oth or OTH (with a letter O)