Conditional Formatting a Planner

Hi all, I am struggling to identify the correct formula to conditionally for a sheet based on several criteria and hoped someone could point me in the right direction.

I am trying to prepare a leave planner which allows staff to record their leave in a central file. This file will grow with time and will ultimately have approx. 200 individual entries for 30 staff members. The attached file shows the structure of this sheet. Based on the sporadic nature of booking leave, each staff members name will appear multiple times in this list as the year progress. What I am trying to do is build a planner in a neighbouring sheet which automatically colour codes cells to show staff members absence across the year.

I am familiar with conditional formatting and the use of formulae but I am finding it difficult to identify one which is able to check the leave that has been booked (on sheet1) and compare it with the date in the planner for sheet 2.

I have not explained this well, but if anyone feels that they are able to assist I will do my best to clarify.

Steve