Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: The "appointed days" [Surah al-Hajj: 28] are the ten days, and the "counted days" [Surah al-Baqarah: 203] are the days of Tashriq.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10145