lder ▁to ▁distinguish ▁him ▁from ▁a ▁ 1 0 th - century ▁Indian ▁math ematic ian ▁of ▁the ▁same ▁name . ▁He ▁fl our ished ▁in ▁K us um ap ura — near ▁P atal i put ra ▁( Pat na ), ▁then ▁the ▁capital ▁of ▁the ▁Gu pta ▁dynast y — where ▁he ▁composed ▁at ▁least ▁two ▁works , ▁A ry ab h ati ya ▁( c . ▁ 4 9 9 ) ▁and ▁the ▁now ▁lost ▁A ry ab hat as idd h anta . ▁▁ ▁A ry ab hat as idd h anta ▁circul ated ▁mainly ▁in ▁the ▁north west ▁of ▁India ▁and , ▁through ▁the ▁S ā s ā n ian ▁dynast y ▁( 2 2 4 – 6 5 1 ) ▁of ▁Iran , ▁had ▁a ▁prof ound ▁influence ▁on ▁the ▁development ▁of ▁Islam ic ▁astronom y . ▁Its ▁contents ▁are ▁preserved ▁to ▁some ▁extent ▁in ▁the ▁works ▁of ▁Var ah ami hi ra ▁( fl our ished ▁c . ▁ 5 5 0 ), ▁Bh ask ara ▁I ▁( fl our ished ▁c . ▁ 6 2 9 ), ▁Bra hm agu pta ▁( 5 9 8 ▁– ▁c . ▁ 6 6 5 ), ▁and ▁others . ▁It ▁is ▁one ▁of ▁the ▁earliest ▁astronom ical ▁works ▁to ▁assign ▁the ▁start ▁of ▁each ▁day ▁to ▁mid night . ▁ ▁A ry ab h ati ya ▁was ▁particularly ▁popular ▁in ▁South ▁India , ▁where ▁numerous ▁mathemat icians ▁over ▁the ▁en su ing ▁mill en ni um ▁wrote ▁comment