When creating a Task manually you are able to set a Due Time for the Task as well as a Due Date. 


If your task is coming from a Job Type Template, you are unable to select the time of the day that it will be due as it will create automatically from the job trigger.


To create the new Task manually, in the Web Portal go to Tasks > +New Task. When you're creating the new task, there will be an option in the settings that will allow you to select a specific time for the Task to be due.