عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((إِنَّ لِلصَّلَاةِ أَوَّلًا وَآخِرًا، وَإِنَّ أَوَّلَ وَقْتِ الظُّهْرِ حِينَ تَزُولُ الشَّمْسُ وَإِنَّ آخِرَ وَقْتِهَا حِينَ يَدْخُلُ وَقْتُ الْعَصْرِ، وَإِنَّ أَوَّلَ وَقْتِ الْعَصْرِ حِينَ يَدْخُلُ وَقْتُهَا وَإِنَّ آخِرَ وَقْتِهَا حِينَ تَصْفَرُّ الشَّمْسُ، وَإِنَّ أَوَّلَ وَقْتِ الْمَغْرِبِ حِينَ تَغْرُبُ الشَّمْسُ وَإِنَّ آخِرَ وَقْتِهَا حِينَ يَغِيبُ الْأُفُقُ، وَإِنَّ أَوَّلَ وَقْتِ الْعِشَاءِ الْآخِرَةِ حِينَ يَغِيبُ الْأُفُقُ وَإِنَّ آخِرَ وَقْتِهَا حِينَ يَنْتَصِفُ اللَّيْلُ، وَإِنَّ أَوَّلَ وَقْتِ الْفَجْرِ حِينَ يَطْلُعُ الْفَجْرُ وَإِنَّ آخِرَ وَقْتِهَا حِينَ تَطْلُعُ الشَّمْسُ))
It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him and his family) said: Indeed, every prayer has a beginning time and an ending time. The beginning time for the Zuhr prayer is when the sun declines (from its zenith), and its ending time is until the time for Asr enters. The beginning time for Asr is when its time enters, and its ending time is until the sun becomes yellow. The beginning time for Maghrib is from the setting of the sun, and its ending time continues until the disappearance of the twilight (shafaq) from the horizon. The beginning time for Isha is from the disappearance of the twilight, and its ending time continues until the middle of the night. The beginning time for Fajr is from the appearance of dawn, and its ending time continues until the rising of the sun.