In my experience it's impossible to do it in a 9-5 day
A typical day started for me at 7:15 setting myself up- photocopying materials, getting all the exercise books to the required rooms, going through emails about messages to pass on to form group.
Then teach 8:45- 3:30.
There was hardly any break time- morning break was spent keeping back pupils, discussing problems, setting up the next classroom or corridor/playground duties
Lunch time involved running lunch-time clubs, other duties or detentions.
After school there was usually either detentions, revision classes, departmental meetings or training until 4.30.
That still left marking and lesson planning.
Imagine how much marking there is. You teach maybe 120 students in a day. If you spend just one minute looking at each book that will take you two hours. Okay, you don't go through the books everyday but maybe once a week you need to go through it all, mark it, set targets. That usually takes all Sunday afternoon.
Lesson planning- you are expected to lodge a written lesson plan showing all the key elements of your lesson, objectives, measures of assessment, differentiation plans. You also need to provide a range of resources- extra sheets for the brighter students, kinaesthetic activities for those learners, resources for the weaker pupils who need support. That can easily be an hour a day.
Then there are reports, parents evenings, exam entries, homework setting and marking, phone calls /meetings with parents. That's more evenings and weekend time
Does this help?