San Francisco Mayor Gavin Newsom, who leapt onto the national stage when he directed the city clerk to issue marriage licenses to same-sex couples in 2004, will be among the speakers at UC Davis' spring commencements.

Newsom, now in his second term as mayor, will speak at the ceremony of the School of Law at 10:30 a.m. Saturday, May 17, at the ARC Pavilion.

Other guest speakers:

California Assembly Speaker Fabian Núñez, D-Los Angeles (School of Education); Booker Holton, principal of Tova Applied Science and Technology in Orinda, Calif., (Graduate Studies); Lee A. McIntire, president and chief operating officer of the engineering consulting firm CH2M Hill (Graduate School of Management); and Craig McNamara, who practices sustainable farming techniques at his Sierra Orchards in Winters and teaches the principles of land stewardship through the Center for Land-Based Learning (College of Agricultural and Environmental Sciences).

UC Davis' 12 commencements:

School of Law — 10:30 a.m. Saturday, May 17, at the ARC Pavilion;

School of Medicine — 10 a.m. Saturday, June 7, at the Mondavi Center for the Performing Arts;

School of Education — 4 p.m. Wednesday, June 11, Mondavi Center;

Graduate Studies — 4 p.m. Thursday, June 12, ARC Pavilion;

College of Biological Sciences — 10 a.m. Friday, June 13, ARC Pavilion;

School of Veterinary Medicine — 10:30 a.m. Friday June 13, Mondavi Center;

College of Engineering — 3 p.m. Friday, June 13, ARC Pavilion;

College of Letters and Science — 9 a.m. and 2 p.m. Saturday, June 14, ARC Pavilion.

Graduate School of Management — 10 a.m. Saturday, June 14, Mondavi Center; and

College of Agricultural and Environmental Sciences — 9 a.m. and 2 p.m. Sunday, June 15, ARC Pavilion.

The campus will offer live and on-demand webcasts of each of the commencements at commencementvideo.ucdavis.edu.