What is the ruling on delaying the Maghrib or Asr prayer by approximately one hour?

There is no limit to the length of a supererogatory (nafl) prayer for an individual (praying alone); it may be lengthened according to one's energy and readiness. As for obligatory (fard) prayers, they must be performed within their designated time. If one is leading the prayer as an Imam, it is prescribed for him to lighten the prayer for the congregants, as the Prophet, peace and blessings be upon him, said: "If any of you leads the people in prayer, he should lighten it, for among them are the weak, the sick, and the old. But if one of you prays alone, he may prolong it as much as he wishes." Prolonging refers to the pillars that allow for it, such as standing, bowing, and prostrating. The predominant guidance of the Prophet, peace and blessings be upon him, for the afternoon ('Asr) and sunset (Maghrib) prayers was to lighten them.