How to load data from various sheets into one master sheet?

Hi Guys,
Hope for an expert in excel who can help!!!

I have a spread sheet that contains:

1st sheet is master file with the number plate number on first column, date of first notice in second column, date of 2nd offence in 3 rd column and so on until 6th notice.

I have other sheets named by month that contain: 1st column Number plate, 2nd column 1st day of the month and so on until the last day of the month.

When the bridging of car park law is noticed, the security guy puts "x" in the day it happened column. There are thousands of number plates and only some of them perform the offence. All the time different number plate, different date...

What I need to get my head around is how to make the data from those monthly sheets flow into my Master sheet. 1 st offence is considered any within 7 days from Wednesday to Wednesday.

Can't get anywhere as its too much data and I am not an expert in Excel. I can build pivot table, do a v-look up but non of these seems to be working :( Will greatly appreciate any help!!!! Thank you in advance!