I don't know if this will help but I found this reference to the Day Family, Ventura County.
David Deneal Day David Deneal Day, 44, of Rancho Cordova, Calif., passed away Nov. 9, 2001, after a lengthy illness. David was born Aug. 26, 1957, and had been a Ventura County resident for 29 years, coming from Northridge. He worked as a roofer. David enjoyed playing the drums and he loved water sports, especially sailing. Now David has set sail into heaven and his dream has come true. He is survived by his wife, Wendy of Rancho Cordova; daughter, Jolene Day of Rancho Cordova; son, Joseph Day of Rancho Cordova; grandchild, Nicholas David Haro of Rancho Cordova; parents, Joseph and Delores Day of Henderson, Nev.; sister, Debbie Gocke of Henderson, Nev.; and nephew, Tony Interrante of Simi Valley. A service will be at 2 p.m. with burial at 3 p.m. Thursday, Nov. 15, at Conejo Mountain Memorial Park.
There is also a Delores Day Park in Fillmore, CA, Ventura County. I couldn't come up with an obit from the Fillmore newspapers for 2003.Sorry. Simi Valley is in Ventura County, so if the nephew is a family member, you might get some contact info.Hope some of this might help.