Estimation column writing Backlog

[Surya Akasam]

Hi 

I am trying to implement this in Jira, I was using Version One earlier not sure how to do it

I want to create a backlog Items like a place holders in Jira, where at this stage These are High level Items may be like epics and there are no estimations at this phase

Once I create all this place holders, I wish to break down them in to stories as per the Definition of Ready 

Then I shall estimate in the Sprint planning meetings respectively. 

Now When i try to create an epic, there is column called Time Estimate which is Mandatory which I am putting Zero

Appreciate any one can help me with the workflow configured

Regards

Surya