A Butsudan (lit. "Buddhist altar") is a shrine commonly found in temples and homes in Japanese Buddhist cultures. A Butsudan usually houses a Honzon, a statue or painting of the Buddha or a Buddhist deity that reflects the school which the family follows, though embroidered scrolls containing a mantric or Sūtra text are also common. Other auxiliary items often found near the Butsudan.

Texts predicting that the Buddhist religion will last only 500 years do not subdivide this figure into smaller periods. With the advent of longer timetables, however, Buddhists began to identify discrete stages or periods within the overall process of decline. A wide range of periodization systems can be found in Indian Buddhist texts. Clearly there was no consensus among Indian Buddhists on the total duration