The fixtures calendar has now been updated to include all fixtures from U8's to U18's. No U-21, Reserve or Senior fixtures (except Gaeltacht) are available yet.
You can now choose to view ALL fixtures together or filter them by age group. So for example if you only want to see the Under 8 fixtures you can just tick that box. You can also choose multiple age groups and they will show up. They are colour coded to make it easier as well.
There is more information on the calendar page (see link on homepage).