The time between 12 am and 3 am is generally considered forbidden for worship, chanting or auspicious works. There is a deep spiritual and scriptural reason behind this. In Hinduism, the night is divided into four prahars, the last prahar of which ends at Brahmamuhurta.

The middle of the night, especially from 12 am to 3 am, is considered to be the demonic period or Tamasik time. This time is under the influence of Tamasik and negative energy. It is believed that during this period, the powers of Tantra, ghosts, vampires, demons remain active. This time is generally for Tantric activities, crematorium sadhna or lowly sadhna. Gods and divine qualities remain dormant at this time, hence worship is ineffective.

Brahmamuhurta vs. midnight
Brahmamuhurta (between 3:30 am and 5:30 am) is considered the best time in the scriptures for meditation, mantra chanting and worship. There is even a verse for this: Brahmamuhurte uttishthet swastho raksharthamayushah: Waking up in Brahmamuhurta is the best for longevity, wisdom and brilliance.