We are deprecating the ability to disable time tracking in Jira Cloud via REST APIs on 16 June 2019.
Support for these APIs will be removed after 16 Jan 2020.
We are no longer supporting the ability to disable time tracking in the Jira Cloud UI and Jira Cloud REST API.
We have found that only a very small number of people have this setting disabled. Removing this setting will improve the experience for configuring time tracking by removing an unnecessary option.
Projects are able to control time tracking by associating or disassociating the time tracking field.