Automation

How can I use the New-OSCustomizationSpec command to create a configuration with a time zone?

But linux-type [VM Customization Specifications] cannot be created with the [-Timezone] option.

You can't.
This is not a PowerCLI thing.
The OSCustomizationSpec for Windows is basically using the Windows sysprep tool with an unattended.txt file.
And there is an option to specify the TimeZone in there.

The Linux OSCustomizationSpec is very limited in its parameters.
That is because there is no sysprep like tool that works for all Linux distributions.

Okay, it seems that I can only edit it manually.

Edit what?

Manually edit the linux configuration file in [VM Customization Specifications] to configure TIMEZONE.

Just wondering which PowerCLI version are you using?

For me the TimeZone parameter is available with OSType Linux

About "You must specify only parameters that belong to the same parameter set, Windows or Linux."

What's the meaning？

Several PowerShell (and PowerCLI) cmdlets have so-called ParametersSets.
In short, some parameters can not be combined with other parameters.
This also goes for the New-OSCustomizationSpec cmdlet, there is a Linux and a Windows parameterset.

In your code the -OSType Linux indicates that you are using the Linux parameterset, and then parameters like OrgName and FullName are not allowed.

I don't see that Linux has the Timezone parameter.

There is indeed an issue with that cmdlet, see also customization specification set timezone linux - VMware Technology Network VMTN

As an alternative, you could use the API directly.
Something like this

Thank you for your enthusiastic answer

I Get the solution
https://communities.vmware.com/t5/VMware-PowerCLI-Discussions/Required-vSphere-Permissions-to-Run-Some-Specific-PowerCLI/td-p/2172653