(a) Ubayd bin Umayr (may Allah have mercy on him) says that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) used to say takbir from after Fajr on the day of Arafah until the Zuhr prayer on the last of the days of Tashriq.
This is how al-Hajjaj bin Artah narrated it from Ata, and Yahya bin Sa'id al-Qattan rejected it, saying: This is an error (wahm) on the part of al-Hajjaj.
(b) The chain from Sayyiduna Umar (may Allah be pleased with him) is only that he used to say takbir in his tent at Mina.
(c) Ata bin Abi Rabah (may Allah have mercy on him) used to say takbir from the Zuhr prayer on the Day of Sacrifice until the Asr prayer on the last of the days of Tashriq. Had Ata had from Umar what al-Hajjaj narrated from him, he would not have allowed himself to differ from Umar; and Allah knows best.
It has also been narrated from Abu Ishaq al-Sabi'i that he reported it from Umar and Ali, and it is mursal.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة العيدين / 6273