What is the best way to authenticate to Google Cloud Storage Bucket from a shell script (To be scheduled to run daily/hourly) using a service account? I have gone through the below link, but I still have some doubts regarding the login process.

Then, add your credential, your role, and click on add condition (you must set the uniform permission definition on the bucket to have available that feature)

And then define a condition to allow the permission after 10am your timezone and before 11am your timezone (you don't have minute granularity)