It is believed that from tamil month, from thai to aani is the day time for devas and from aadi to margali is the night time for devas. During this night time we will have plenty poojas and pithru pooja. In the month of aadi you have to hear upanyasams, you can read ramayanam, bhagavadham, and also devi pooja and reading devi bhaghavatham,
You can read devi mahathmyam, soundarya lahari, kadga mala , lalitha sahasranamam and vishnu sahasranamam. and all other stothrams you like to read.In aadi chevvai read durga slogams. In aadi friday lalitha sahasranamam. In some districts in south aadi cheevai is being celebrated and in other districts in tamil nadu fridays are important.