According to the TREC promulgated Seller's Temporary Lease, how long does the landlord have to itemize and provide to the tenant any deductions to the security deposit?

30 days.

Explanation:

It is illegal for the landlord to deduct from the security post because it belongs to the tenant. But if there is any damage or breach by the tenant, the landlord can deduct the security post. In this case there must a 30-day advance notice stating that the tenant will forfeit the right to security post.