Is it different from the well known s'ubhatva (benefic status) and as'ubhatva (malefic status) of grahas in a chart based on their position from the lagna of the subject (person) ?
Naturally malefic turns into benefic if he owns the 4th, 7th or 10th houses from lagna (ascendant) . Owner of the 5th and 9th houses is benefic whatever is its shubhaashubhatva naturally.
Saturn is the owner of Makara(Capricorn) and Kumbha (Aquarius) houses.
For Tula (libra) lagna for example, these two are 4th and 5th respectively. Thus for this lagna, Saturn is benefic in both the positions.
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I just found that if 71/2 S'ani occurs for the second time in life, it is called pongu s'ani in Tamil.