Some sources give the date of the Buddha's birth as 563 BCE and others as 624 BCE; Theravada Buddhist countries tend to use the latter figure. This displaces all the dates in the following table about 61 years further back. See Theravada Buddhism. The difference between the two reckonings seems to have occurred at sometime between the reigns of the Sri Lankan kings Udaya III (946-954 or 1007-1015)and Pârakkama Pandya (c. 1046-1048), when there was considerable unrest in the country.