What are the prescribed times for supererogatory (Nawafil) and regular (Rawatib) optional prayers?

Supererogatory prayers (nawafil) are permissible at all times except during the prohibited times: from the appearance of the second dawn until sunrise, when the sun is at its zenith until it declines, and after the Asr prayer until sunset. This is based on the Prophet's (peace be upon him) saying: "There is no prayer after the Fajr prayer until the sun rises, and no prayer after the Asr prayer until the sun sets."

Supererogatory prayers are divided into confirmed regular supererogatory prayers (ratibah mu'akkadah), which are twelve rak'ahs: four before Dhuhr and two after it, two after Maghrib, two after Isha, and two before Fajr. And non-confirmed regular supererogatory prayers (ratibah ghayr mu'akkadah): four before Asr, two before Maghrib, and two before Isha.