Acc. to Devi MahAtmya (a.k.a. ChanDi pATh) section of MArkanDeya purAN KAli manifested on ashTami, from DurgA's adnyA chakra (third eye).
Regarding DurgA -- the composite shakti of VishweDeva (all Devas) -- DurgA is primarily VishNu's shakti , combined with shakti of all Devas (Indra...) - which in turn are parts/aspects of NArAyaN-VishNu... So the combining was not in time acc. to me.
Also because VishNu initiated this.
People equate DurgA = pArvatI which is OK, because Adi-Shakti is One, and the rahasya-trayam says the secret original Adi-Shakti which "created" the Tri-Dev-N-Tri-Devis per BramhAnDa (acc. to mArkanDeya purAN) is MahALakshmi ! Which is Shri . The mahAlakshmi of KolhApur is that.
Which circles back to the fact that DurgA is primarily MahAVishNu's shakti i.e. MahALakshmi
*I like DrikPanchang too. Most trustworthy - especially for the JanmAshTami niSit kAl ..