Are all the daily and nightly adhkar (remembrances) considered Sunnah if one is consistent in reciting them, and what is the ruling on reciting only some of them?

Persevering in the morning and evening adhkar (remembrances) is a great act of worship and protection for the Muslim. They are from the established Sunnah and are not obligatory. Whoever recites all of them has been granted a great good. As for one who recites only some of them due to inability or preoccupation, there is no sin upon him. Al-Nawawi said: "Whoever is enabled to perform all of them, then that is a blessing and grace from Allah Almighty upon him, and glad tidings for him. And whoever is unable to perform all of them, let him confine himself to as much as he wishes from their abridged forms, even if it be a single dhikr." Therefore, a Muslim should be keen on them to attain the reward, and if he recites only some of them, he will have the reward proportionate to what he has recited, and there is no sin upon him.