It is the eve of Navratri, the Festival of Nine Nights of celebration of and devotion to divine Devi.
Each night, an aspect of Maa Durga is celebrated with Durga Puja.
In some observances, Maa Shakti is celebrated with the first three nights devoted to aspects of Durga, the middle three to Lakshmi, and the final three to Saraswati.
It is a festival celebrating the victory of the Goddess Durga over Evil, restoring peace, harmony, and balance to the world. With everything current, this will be a particularly poignant Navratri- for not just myself- but many others who observe it, I'm sure.
Jai Durga Maa!