Re: at what times is it prohibited to pray..
If I can remember all correctly:
From sunrise till the point when sun is about a distance of "sawaa Nezay" from horizon (calculated to be between 15-20 minutes after sunrise), Ishraq time - Makrooh time
Noon: when exactly in the middle of the day (Nisf-un-nahaar) uptil 15-20 minutes - Makrooh time
After offering As'r prayer [qadhaa for other fardh can be done though] - Prohibited time
15-20 minutes before sunset (when sun is on a distance of "sawaa Nezay" from horizon ) till sunset, Maghrib time - Makrooh time