Given dates (all in the Common Era) are approximate and represent the upper and lower possible extremes of the person's lifetime.
Since he mentions Dharmakīrti in the maṅgala verse and is clearly influenced by him in his interpretation, he can hardly be identical with the grammarian of the same name (cf. also Kobayashi 1977; but for a divergent view cf. Hayes 1993), provided the dating of the grammarian Jinendrabuddhi (around 700) according to Cardona 1976 p. 281, is right; life dates: ca 8th-9th century (cf. Ruegg 1959 p. 132), 2nd half 8th century. (cf. Funayama 1995).