Matsya Purana 273.42

273.42

ebhiḥ pravartate kālo divyaḥ saptarṣibhistu vai.
saptarṣīṇāñca yau pūrvau dṛśyete hyuditau niśi .. 273.41

This is the cycle of the Great Bear, and is remembered as being, according to divine reckoning, 6 divine months and 7 divine years. According to those constellations divine time proceeds by means of the Great Bear, (41a) (Pargiter)

The two front stars of the Great Bear, which are seen when risen at night, the lunar constellation which is seen situated equally between them in the sky, the Great Bear is to be known as conjoined with that constellation 100 years in the sky —42 43 (Pargiter)