If you include the date and time information in task name when creating a new task, TickTick will automatically recognize the date as the due date and set a reminder based on the time.
For example, if you want to go to gym tonight at 8, just type: "Go to gym at 8pm", a reminder with a new task will then be created.
Note:
If you prefer to have the date and time removed from task name when using smart date parsing, go to Settings > Task Quick Add > Smart Recognition > Smart Date Parsing, then select "Remove Text in Tasks".
Here're some examples of the date formats you can use in TickTick.