Modification and setup of open source web calendar

Modification and setup of open source script (Proverbs Web Calendar 2.1.2a) using PHP and powered by MySQL on our server. Our demands for the script would be: 5 user accounts 1 administrator account Each day in a week should by administrator selected for either studio 1 (light green background for the whole day) studio 2 (light blue background the whole day) editing (light red backround the whole day) Entries should be possible for every hour from 8.00 am to 20.00 pm. Every hourly entry should have the following fields: Name: Phone nr: Job Description: Pickups: Cross entries should not be possible, several users should be able to be logged on simultanously, without editing the same entry. Every entry or change should launch an email to a preselcted email address containing the changes. It should be possible to backup the entire diary on a weekly basis.