cchopeful
Ok you can do 210 hrs in 28 consecutive days (roughly speaking your rostered month)
But still 900 hrs in 12 consecutive months.
So you can do upto 210 hrs a month but not exceed 900 hrs within a 12 month period. You could in theory work max hours each month but when it comes close to your 900 hrs before the 12 month period rostering will have to cut your flying right back so you dont go over.
Hope thats not to confusing