No classes on full or new moons.  
Times given are specific to Santa Cruz:

2020
January 10 - Friday - Full at 11:21 AM 
January 24 - Friday - New at 1:42 PM
February 8 - Saturday - Full at 11:33 PM
February 23 - Sunday - New at 7:32 AM
March 9 - Monday - Full at 10:47 AM
March 24 - Tuesday - New at 2:28 AM
April 7 - Tuesday - Full at 7:35 PM
April 22 - Wednesday - New at 7:25 PM
May 7 - Thursday - Full at 3:45 AM
May 22 - Friday - New at 10:38 AM
June 5 - Friday - Full at 12:12 PM
June 20 - Saturday - New at 11:41 PM
July 4 - Saturday - Full at 9:44 PM
July 20 - Monday - New at 10:32 AM
August 3 - Monday - Full at 8:58 AM
August 18 - Tuesday - New at 7:41 PM 
September 1 - Tuesday - Full at 10:22 PM
September 17 - Thursday - New at 4:00 AM
October 1 - Thursday - Full at 2:05 PM
October 16 - Friday - New at 12:31 PM
October 31 - Saturday - Full at 7:49 AM
November 14 - Saturday - New at 9:07 PM
November 30 - Monday - Full at 1:29 AM
December 14 - Monday - New at 8:16 AM
December 29 - Tuesday - Full at 7:28 PM