checkbox

Hi, I created a custom field for item and it is using "Check Boxes" as Field Type. (this field let users to choose their time of working during a day) (Imagine a user choose this hours: 8, 9, 10, 11, 12, 16, 17, 18, 19) Now it shows like this to users: 8 9 10 11 12 16 17 18 19 How can I set it...