Short answer: Yes—Jain householders may eat dates (khajur/kharek) in Chaturmās, unless you have taken a specific tyāg that forbids them.

Keep these Jain rules in mind:

• Check carefully for worms/eggs; avoid old or infested dried dates.
• No fermentation or alcohol: date wine/vinegar/syrups made by fermentation are forbidden.
• No honey-mixing: if a date product contains honey, it is not allowed.
• Same-day, daylight, and saṃyama: eat before sunset; use filtered water; avoid if it breaks a vow like chovihār, upavās, ekāsan, or a phalahār-only rule that excludes such items.
• Vow-specific: many take extra Chaturmās niyams (e.g., dry-fruit tyāg, sugar/gur tyāg, certain taste-tyāg). If you’ve adopted such a niyam, then avoid dates accordingly.

Traditions:

• Śvetāmbara and Digambara householders follow the same principle: fruits like dates are permissible in Chaturmās unless personally renounced; practices can vary by guru/saṅgh, so follow your ācārya’s guidance.

In sum: Dates are generally permitted in Chaturmās for lay Jains, provided they are fresh, insect‑free, non‑fermented, and do not violate your chosen vows or your guru’s instructions.