Sayyiduna Ibn Umar (may Allah be pleased with them both) said regarding the fast of the Day of Arafah that neither the Prophet (peace and blessings be upon him) nor any of the three caliphs observed the fast on that day.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5411M
Hadith Gradingحکم دارالسلام:حديث صحيح كسابقه ، وهذا إسناد ضعيف لإبهام الراوي عن ابن عمر .