[sdk]: Block storage resource get volume created at time

Hello there, Hope this email finds you well. I have a question for getting the volume created at time using the openstacksdk block storage volume class. I found that the attribute volume.create_at is in a format like "2021-05-28T17:16:45.000000", and we don't know the timezone for it. Wondering if the openstack always uses the GMT? or anywhere we could set it to our pacific time? Thanks and have a great day! Catherine