Connecting OpenVPN to Endian Firewall

Hi, I have an endian firewall that I am trying to connect to using OpenVPN. I have created a user, downloaded the certificate and installed it to my client. When I connect, I type in the username and password and it returns an error that says "Unable to connect because the certificate is not yet valid". Has anyone else had any experience with this? Endian VPN logs say "connection refused" whenever it tries to connect.