When installing Microsoft Windows Essential Business Server in Hyper-V setup may fail due to issues caused by time zone settings. EBS setup does not expose either clock time or time zone settings during setup and always installs with a PST time zone. Hyper-V children will synch their BIOS time with that of the parent. If the parent partition is in a time zone other than PST, setup will fail.

Resolution: When installing in a virtualized environment, set the time zone of the parent partition as PST with the correct time. Do not modify time or time zone until you have completed the setup of all 3 servers. Once setup is complete you can change the time zone to the correct time zone for all servers including the Hyper-V Parent server.

More info: EBS Blog