Where does deployment for stage in Amazon API Gateway come from?

When I create a stage in API Gateway, I need to set the deployment date. When I click the drop down, there are a couple of dates listed in there but I don't know how were they generated. I can't even write the date manually, so I am just wondering where do the items in the list come from anyway?

Solution

As per the AWS API Gateway docs - "From the Deployment drop-down list, choose the date and time of the existing API deployment you want to associate with this stage.".

When you create a stage, you will see all the deployments (and switch between them) in the Deployment History tab for stage. So it's more of a read-only list that represent moments when you did deployments to API Gateway.