Date of founding of the department

According to the "Historical Overview: San Diego" over at the University of California History digital archives, the department of philosophy at UCSD was established in 1963 just before the University was opened to undergraduates:

The campus had already branched into fields other than science and engineering with the establishment of Departments of Philosophy and Literature during 1963. In the fall of 1964, the campus opened for undergraduates offering a basic lower division curriculum preparing students for upper division majors in the humanities, the social sciences, the biological sciences, the physical sciences, and mathematics. A total of 181 freshmen enrolled in the pioneering undergraduate class.

One can put this in perspective relative to the establishment of the "University of California, San Diego" in 1960, which had previously been known as an "Institute of Technology and Engineering".

The first faculty appointment for the School of Science and Engineering was made in July, 1957, and was supported by a large grant of funds from the General Dynamics Corporation. By June 30, 1959, seven faculty appointments had been made and a total of 36 appointments had been approved for the 1959-60 fiscal year. The school enrolled its first graduate students in 1960 in the physical sciences.

From this beginning, the program was rapidly developed in the humanities and social sciences. By the mid-1960's, research ranged from the problems of cosmochemistry to studies of seventeenth-century philosophy. The teaching program reflected a broad spectrum of learning, with offerings in aerospace and mechanical engineering sciences, applied electrophysics, biology, chemistry, earth sciences, economics, history, languages, linguistics, literature, philosophy, physics, and psychology.

The Regents on November 18, 1960, selected the University of California, San Diego, as the name for the general campus in the La Jolla-San Diego area.