Although not a perpetual license, this will fix the time limitation (for home lab use)

1. Install Omnissa Horizon
2. [OPTIONAL] Use license key. Use a modified .ini file and the UKG generator. If you do not have knowledge about this, use:
Omnissa Horizon 8.0 Enterprise Suite (Named User):
5G20H-0AH9K-089C0-W10QM-978L4
4A69K-0VL4H-H89D9-G30G6-07HP0
MC410-0M39K-48988-MV1EK-1L054
Omnissa Horizon 8.0 Enterprise Suite (concurrent):
NF012-0XK0H-H89K9-708X4-CLAL0
HA29K-4ML8H-H89L1-NVCQ4-CC020
5V29H-08J8K-H81N0-0287H-8YU70
4U482-0KH82-08158-8R0GK-C38L0

Note: installing the license will make it possible to extend the grace period with unlimited time.
Without it, it seems there is a 499 day max limit (heard, not tested).
3. Open ADSI edit.
4. Connect to the local ADAM instance, e.g. Connection Point = DC=vdi,DC=vmware,DC=int
5. Browse to: OU=Global,OU=Properties,DC=vdi,DC=vmware,DC=int
6. Edit value CN=Common
7. Select: pae-NameValuePair
8. It should be empty. Add the following 3 values, to create a 3650 days grace period (see picture as reference):

cs-maxDaysToUpdateLicense=3650
samlencryptionkeyvaliditydays=3650
cs-samlsigningkeyvaliditydays=3650

9. Reboot

After logging in to the Omnissa Horizon console you should see a message with the new grace period.
Note: the days expired after the original end of the grace period will be deducted from the days entered!



*: alternatively, use PowerShell for steps 3 to 8:

$dn = "CN=Common,OU=Global,OU=Properties,DC=vdi,DC=vmware,DC=int"; Set-ADObject $dn -Replace @{'pae-NameValuePair'= @(((Get-ADObject $dn -Properties pae-NameValuePair).'pae-NameValuePair' + 'cs-maxDaysToUpdateLicense=3650','cs-samlencryptionkeyvaliditydays=3650','cs-samlsigningkeyvaliditydays=3650') | Select-Object -Unique)}