In Jainism, the answer is about temple maryādā (rules), not about a woman being “bad” or sinful.

1. Are women allowed in temple during periods?

• Generally followed practice in many Jain families:

- During active periods (rajasvalā), women usually do not: - Enter the garbhagriha (inner sanctum). - Touch murtis, scriptures, or puja items. - Do abhishek / dravya-pūjā / ārtī etc. ( jainknowledge.com) - This is called a state of temporary aśaucha (ritual non‑fitness) for certain temple rituals.

• What they can do:

- Recite Navkar Mantra, stavans, do bhāv-pūjā, meditation, pratikraman, listen to pravachan. - In many Śvetāmbara sanghs, women may sit outside the sanctum and do darshan or listen, as per local rules. ( jainknowledge.com)

2. Is this from scriptures or just custom?

• There is no single Jain scripture that clearly says:

“Women must not enter temple during periods.” ( jainknowledge.com)

• These are traditional maryādā based on:

- Temple ritual cleanliness (pujā‑śuddhi). - Practical hygiene and giving women rest.

• The soul (jīva) is always pure; only the outer ritual fitness changes for a few days. ( jainknowledge.com)

3. Digambar & Śvetāmbara difference (general trend)

• Digambar:

- Usually stricter. - Often advise: during periods do not enter temple premises or handle scriptures/puja items; focus on bhāv‑bhakti from home. ( jainknowledge.com)

• Śvetāmbara:

- Commonly: avoid garbhagriha and idol-touch, but in many places distant darshan / pravachan is allowed; follow local sangh rules. ( jainknowledge.com)

4. When can she go again?

• Normally, after:

1. Bleeding has fully stopped, and 2. She takes a full bath and wears clean, washed clothes. ( jainknowledge.com)

5. Main point to remember

• Jain Dharma does NOT say that a woman herself becomes impure or inferior.
• Menstruation is a natural body process; rules are only about how to do temple rituals in those days, and they also vary by family, sangh, and country. ( jainknowledge.com)

You can read a simple explanation here