There were three times at which the Messenger of Allah ﷺ used to forbid us to pray or bury our dead - when the sun begins to rise till it is fully up, when the sun is at its height midway till it passes the meridian, and when the sun draws near to setting till it sets, or as he said.  

ثَلاَثُ سَاعَاتٍ كَانَ رَسُولُ اللَّهِ ﷺ يَنْهَانَا أَنْ نُصَلِّيَ فِيهِنَّ أَوْ نَقْبُرَ فِيهِنَّ مَوْتَانَا حِينَ تَطْلُعُ الشَّمْسُ بَازِغَةً حَتَّى تَرْتَفِعَ وَحِينَ يَقُومُ قَائِمُ الظَّهِيرَةِ حَتَّى تَمِيلَ وَحِينَ تَضَيَّفُ الشَّمْسُ لِلْغُرُوبِ حَتَّى تَغْرُبَ أَوْ كَمَا قَالَ