I never saw the Prophet ﷺ offering any prayer not at its stated time except two; he prayed the Maghrib and the ʿIsha' together and he offered the morning prayer before its usual time.  

مَا رَأَيْتُ النَّبِيَّ ﷺ صَلَّى صَلاَةً بِغَيْرِ مِيقَاتِهَا إِلاَّ صَلاَتَيْنِ جَمَعَ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ وَصَلَّى الْفَجْرَ قَبْلَ مِيقَاتِهَا  

I went out with ʿAbdullah , to Mecca and when we proceeded to am' he offered the two prayers (the Maghrib and the ʿIsha') together, making the Adhan and Iqama separately for each prayer. He took his supper in between the two prayers. He offered the Fajr prayer as soon as the day dawned. Some people said, "The day had dawned (at the time of the prayer)," and others said, "The day had not dawned." ʿAbdullah then said, "Messenger of Allah ﷺ said, 'These two prayers have been shifted from their stated times at this place only (at Al-Muzdalifa); first: The Maghrib and the ʿIsha'. So the people should not arrive at Al-Muzdalifa till the time of the ʿIsha' prayer has become due. The second prayer is the morning prayer which is offered at this hour.' " Then ʿAbdullah stayed there till it became a bit brighter. He then said, "If the chief of the believers hastened onwards to Mina just now, then he had indeed followed the Sunna." I do not know which proceeded the other, his (ʿAbdullah's) statement or the departure of ʿUthman . ʿAbdullah was reciting Talbiya till he threw pebbles at the Jamrat-Al- ʿAqaba on the Day of Nahr (slaughtering) (that is the 10th of Dhul-Hijja).  

خَرَجْنَا مَعَ عَبْدِ اللَّهِ ؓ إِلَى مَكَّةَ ثُمَّ قَدِمْنَا جَمْعًا فَصَلَّى الصَّلاَتَيْنِ كُلَّ صَلاَةٍ وَحْدَهَا بِأَذَانٍ وَإِقَامَةٍ وَالْعَشَاءُ بَيْنَهُمَا ثُمَّ صَلَّى الْفَجْرَ حِينَ طَلَعَ الْفَجْرُ قَائِلٌ يَقُولُ طَلَعَ الْفَجْرُ وَقَائِلٌ يَقُولُ لَمْ يَطْلُعِ الْفَجْرُ ثُمَّ قَالَ إِنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّ هَاتَيْنِ الصَّلاَتَيْنِ حُوِّلَتَا عَنْ وَقْتِهِمَا فِي هَذَا الْمَكَانِ الْمَغْرِبَ وَالْعِشَاءَ فَلاَ يَقْدَمُ النَّاسُ جَمْعًا حَتَّى يُعْتِمُوا وَصَلاَةَ الْفَجْرِ هَذِهِ السَّاعَةَ ثُمَّ وَقَفَ حَتَّى أَسْفَرَ ثُمَّ قَالَ لَوْ أَنَّ أَمِيرَ الْمُؤْمِنِينَ أَفَاضَ الآنَ أَصَابَ السُّنَّةَ فَمَا أَدْرِي أَقَوْلُهُ كَانَ أَسْرَعَ أَمْ دَفْعُ عُثْمَانَ ؓ فَلَمْ يَزَلْ يُلَبِّي حَتَّى رَمَى جَمْرَةَ الْعَقَبَةِ يَوْمَ النَّحْرِ