The user can render the definition or instance by right click on the definition folder name as shown below: 

The definition or instance is rendered when clicked on “Render definition (Render instance for instances)”  and the critical path of the definition or instance when clicked on the “Render Critical Path”:

All date/times are stored within the database as UTC and displayed based on local timezone of the user. 

Note: Engine runtime data are in ISO + UTC format. 

In the new version 9.10, a new algorithm for critical path calculation shall now render the definition quicker. The workflow definition project report to XLS now shows Critical Path items. Critical path calculation for definition and instances are based on timezone for steps like milestone and waitForDatetime. When time zone calculation is null (datediff between getdate and getutcdate) then the calculation considers the UTC date for current date for all steps.