Simplify/Reword flexible hours section of an employment contract

Hello,

I require an a UK HR professional with legal expertise to re-word/simplify the below section of my employment contract so that it is simpler.


8. Hours of Work
8.1 From the period of January 4th 2021 - January 17th 2021 the normal working hours of the Employee will be 35 hours per week at such times Monday- Friday 9am - 5pm.
8.2 From January 18th 2021 onwards the normal working hours of the Employee will be flexible with a minimum of 14 hours per week and maximum of 35 hours per week at such times Monday - Friday 9am - 5pm.
8.3 The Employee will be entitled to an hour's unpaid lunch break during each working day.
8.4 It may be possible for the Employee to work weekends should the business require. The Employer will agree in advance with the employee via email should they be required to work on a weekend.

What I'm trying to say is:

They employee will work full time Monday to Friday from January 4th to January 17th.
Then (because the employee is a student) they will switch to a part time employee with a minimum of 2 days per week (Monday - Friday). - Maybe this should just state that the hours will be flexible and agreed in advance? In advance as the employee will get their term timetable and we will agree that they will work on the days they are not at University.
There may also be the option for the employee to work some weekends. Weekend work must be agreed in advance in writing via email and is not guaranteed - it depends on the business requirements.
Hourly rate at the weekend is the same as during the week.
No more than 35 hours per week.


Regards,
Jonathan