Discount Settings Help

Hi

Ca anyone help me on

  1. Set user level discounts (eg. Cashier can give max 30% discount, Waiters can give 10% and Admin can give any discount)

  2. Setting up automatic Discount for a date range (eg. Need to setup 20% discount on all products from 6th Jan to 15th Jan)

Please help with links to already in the forum or how to setup the above

First I guess just make calculation buttons for each % and mapping to user role.
Other one look at think21 age check and or happy hour without triggers using rule constraints and apply discount based on date constraint.