I attended the 'Id (prayer) along with 'Umar. He offered prayer before the sermon. He then said: The Messenger of Allah ﷺ prohibited fasting on these two days. As regards Id al-Adha, you eat the meat of your sacrificial animals. As for 'Id al-Fitr, you break (i.e. end) your fast.  

شَهِدْتُ الْعِيدَ مَعَ عُمَرَ فَبَدَأَ بِالصَّلاَةِ قَبْلَ الْخُطْبَةِ ثُمَّ قَالَ إِنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنْ صِيَامِ هَذَيْنِ الْيَوْمَيْنِ أَمَّا يَوْمُ الأَضْحَى فَتَأْكُلُونَ مِنْ لَحْمِ نُسُكِكُمْ وَأَمَّا يَوْمُ الْفِطْرِ فَفِطْرُكُمْ مِنْ صِيَامِكُمْ  

The Messenger of Allah ﷺ forbade fasting on two days, al-Fitr (breaking the fast of Ramadan) and al-Adha (the day of sacrifice), and wearing a tight single garment the raising of which discloses private parts, and sitting with one's legs drawn up and wrapped in one's garment, and forbade praying at two hours, after the Fajr prayer and after the Asr prayer.  

نَهَى رَسُولُ اللَّهِ ﷺ عَنْ صِيَامِ يَوْمَيْنِ يَوْمِ الْفِطْرِ وَيَوْمِ الأَضْحَى وَعَنْ لِبْسَتَيْنِ الصَّمَّاءِ وَأَنْ يَحْتَبِيَ الرَّجُلُ فِي الثَّوْبِ الْوَاحِدِ وَعَنِ الصَّلاَةِ فِي سَاعَتَيْنِ بَعْدَ الصُّبْحِ وَبَعْدَ الْعَصْرِ