Not only can you re-order workouts within a day, you can also move planned workouts from one day to another day from both the Month calendar view and the Week calendar view.
Option 1: Drag & Drop
Step 1
Hover over a track event. 
Step 2
Once the background color of the event changes, click and hold.
Step 3
Drag the workout to the new location.
*Note: You can Drag & Drop workouts both within a day and across days.
Limitations
The only limit with Drag & Drop comes in the Month view. If you have more than 1 track selected, you will NOT be able to use the Drag & Drop feature. When you select more than 1 track while in Month view, a toast notification will appear at the bottom of the screen letting you know Drag & Drop has been disabled.
Option 2: Edit A Tack Event Date
You can also update the actual date of the programmed track event.
Step 1
Double click on a programed track event.
Step 2
Change the date in the "Date" field. 
Step 3
Click the "Update Workout" button. 
Your workout will appear on the new date in whatever calendar view you have selected.
