Ok, I noticed another problem when I tried to separate the date and time field.
I can't create a time field, where a user can choose a time after they use the calendar pop up to choose the date. I believe bc if the user have the option to choose the time, it will be difficult because each hour have 60 minutes and there are 12 hours,
12 times 60 = 720, so there would be 720 options which is a lot.