The Anupiaka, the extra-canonical Pli literature of Buddhism, falls into three historical periods (classical, commentarial and modern) beginning from about the 3rd century BC.
The Anupitaka (Pali, literally, meaning "after pitaka") is the collected non-canonical or extra-canonical Pali literature of Buddhism. The non-canonical or extra-canonical Pali literature can be regarded as falling into three historical periods. The first ("classical") period stretches from about the 3rd century BC to about the 5th century AD. The second ("commentarial") period extends from the 5th century to the 11th century, and the third ("modern") period begins with the 12th century. 
