OS X El Capitan installer certificate expired again?

[DanJ_LRSFC]

Has the certificate on the OS X El Capitan installer expired again (I read that it happened February 2016 last time)? I'm having an issue where even if I redownload the installer it fails to run, the only way I could do it was by putting it on USB and then going into Terminal when booted off the USB, to turn the date back.

Anyone else having this issue?

Thanks,
Dan Jackson (Senior ITServices Technician)
Long Road Sixth Form College
Cambridge, UK.

[howardgmac]

The El Capitan download I got from the App Store this morning shows an expiration date of October 24, 2019 on the certificates.