Al-Bīrūnī (a Persian scholar in the 11th century) computed angles on minutes, seconds thirds (60ths of a second), and even fourths (60ths of thirds). I believe

Al-Bīrūnī (a Persian scholar in the 11th century) computed angles on minutes, seconds thirds (60ths of a second), and even fourths (60ths of thirds). I believe he suggested time could be divided by these units as well, although I can't find the exact reference, so I could be wrong on that count.