Answer

Yes, you can learn the 12 Atichar sutra at that time if your mind is calm and you can focus properly.

Explanation

In Jain Dharma, the most important thing is shuddh bhav — pure intention and attentive recitation. There is no strict rule that a sutra can only be learned in a particular hour.

That said:

• If 12 am to 1 am is quiet for you, you may study then.
• If you feel sleepy or unfocused, another time would be better.
• For learning and memorization, a peaceful and alert mind is more helpful than a fixed clock time.

Spiritual Understanding

Learning a sutra with respect, concentration, and sincerity is what matters most. Jain practice values:

• awareness
• discipline
• purity of mind
• सही उच्चारण and reverence

So the best time is when you can truly absorb the meaning and recite it with devotion.

Takeaway

Yes, you may learn it from 12 am to 1 am, but choose the time when your mind is fresh, peaceful, and fully attentive.