The Lua error in Module:Unicode_data at line 293: attempt to index local 'data_module' (a boolean value)., also known as Lua error in Module:Unicode_data at line 293: attempt to index local 'data_module' (a boolean value)., is a traditional calendar system which began during the reign of Emperor Kōtoku in the 7th century. This calendar has been in use in Japan since the beginning of the 8th century.