how long does the trustee have after death to give benificiaries an accounting of assets.

I'm sorry, but this is not a simple question to answer.  The true answer is, it depends on the circumstances.  The scope of a trustee's duty to account and to report information is governed generally by Prob C §§16060–16069 (general and specific duties, and exceptions), §§15800, 15802–15805 (beneficiaries entitled to notice), and the provisions of the trust instrument concerning accounting and reporting of information. The trustee's statutory duties vary depending on whether the trust is a revocable trust, an irrevocable trust, or a testamentary trust still subject to continuing court supervision. Furthermore, the duties can be modified by the terms of the trust instrument so as to be more stringent against the trustee. See Prob C §16000 (trustee required to administer trust according to trust instrument).