date 0923020415), the installation worked without a problem. date 03061225616) and it did not work because I installed 'El Capitan OS X installer.app' around Sept 2015 and the digital signature/certificates for my installer had expired by now. When I got this error while reinstalling El Capitan OS X, I set the date to today's date (i.e. You have to remember the date you installed 'El Capitan OS X installer.app' into your Application folder. I think many people think setting the date to the current date automatically fixes the issue, but this is not the case. By the way this is not a date time issue, date is correct on my computer.
