Does Zhur (Dhuhr) prayer end at the first or second time for Asr?

So if you look at a number of calendars you'll find that there are two start times for Asr. Now why is this the case? At the time of the Prophet Muhammad, sallallahu alaihi wasalam, when the angel Gabriel was teaching him the Salah, one day he came at a slightly earlier time for Asr and another day he came at a slightly later time. Both hadith collected by Muslim, both authentic hadith. So a number of scholars, the majority of scholars, would base the start time for Asr on the earlier time when the angel Gabriel came one day. The Hanafi madhab, for example, based on the later time and there are evidences other than this, but this is just summarizing the issue. So if you were to pray at the earlier time or the later time, both hadith are authentic, either is fine, your Salah will be valid. Even in the Hanafi madhab, if you were to pray at the earlier time, then there is still leeway and your Salah will still be valid, although in the Hanafi madhab it's recommended to pray at the later time. Allah subhanahu wa ta'ala knows best.