According to Zephyrin Engelhardt, Lasuén wrote that "the faculty to administer the Sacrament of Confirmation" was granted to some of the padres for ten years and then renewed for ten more (but that more than half of the elapsed time was wasted waiting for documents). Lasuén concurs with Payeras that the faculty lapsed in 1795, so it may have started in 1775. However, according to Bolton's Guide to Materials for the History of the United States, in 1787 the faculty was conferred to Lasuén.
In 1820 confirmations were still impossible, according to Payeras. From 1835 the "vice-comisario" Fr. Moreno was able to confirm people. California got its first bishop (inherently able to perform confirmation), Garcia Diego, in 1840. He toured the state administering confirmation, and didn't visit Baja California, but appointed some of the last missionaries there vicars so that they too could exercise the sacrament.
So there may have been a forty year gap with no confirmations in California; the gap lasted at least twenty-five years. Lack of valid holy oils was another major obstacle to performing confirmation.