Bhaktamar Stotra can actually be recited anytime, if it is done with shraddhā (faith) and shuddha bhāv (pure feelings). Still, our Jain ācāryas and tradition suggest some especially good times:

1. Brahma-muhūrta (early morning)

- About 1–1.5 hours before sunrise. - After bath, in clean clothes, before starting other work. - This is considered the best and most satvik time.

1. Morning after snātra-pūjā / darshan

- After doing basic pūjā or temple darshan, sitting peacefully and reciting Bhaktamar is very common.

1. Sandhyā time (evening)

- Around sunset or after pratikraman in the evening. - Mind is calmer, so recitation has good effect.

1. On special days / during special sādhanā

- Paryushan, Ayambil Oli, tithis like Poonam / Ashtami. - Also when someone is sick, in trouble, or starting some important work.

Important points:

• Body and place should be clean.
• Sit in a quiet place, on āsan, with straight posture.
• Start with Namokār Mantra, end with kṣamā-yāchanā (asking forgiveness).
• Do not recite while eating, lying down, in toilet, or doing full attention-driving work.

So, there is no “forbidden” time in Jain Dharma; but early morning or after pratikraman, in a clean and peaceful state, is considered most ideal for Bhaktamar Stotra.

You can read more here