To add a note to a future date in the register please go to Register > Manage Register.
Select the student and date you wish to add the note to and click onto view register.
Once the date is showing if you click into the red box you will have an option to add a note and save.
Once saved if you do not require a specific code to be entered please click back into the box and remove code. The note will still be saved in the background but no code will have been entered for the date. You can also add the code for example if the note is for a medical appointment you may wish to add the code in advance.