There seems to exist a relatively common opinion about the apocalyptic circles in Judaism, which Dr Russell in his book on Jewish apocalyptic expresses in these words: ‘In answer to the prophets’ cry ‘How long, O Lord, how long?’, the apocalyptists gave the year, the day and the hour'. And in his classical study, Die Eschatologie der jüdischen Gemeinde, P. Volz stated: ‘Die zahlenmässige Berechnung des Weltendes ist vor allem das characteristische Geschäft des Apokalyptikers.’