Legal Question in Wills and Trusts in California

The people entitled to the assets of a trust are beneficiaries; heirs are the people who receive the assets from an estate via probate, etc. There is no time limit.

Although there is no waiting period for distribution, the trustee might want to wait until he/she sends out "Notification by Trustee" to all the beneficiaries of the trust and heirs at law to see if anyone is going to contest to trust before making any distribution out of the trust. Another good reason for waiting is the make sure all the debts are paid beforehand before distributing remaining assets.

I assume you mean beneficiaries under the trust, not heirs. Often, a Trustee will wait to see if there is a contest likely and to be sure the creditors are paid before making an distributions but there is no requirement the Trustee wait 6 months before making such a distribution. There are reasons to wait as mentioned.