The Roman History · Amm. 26.1.7

When Valentinian arrived in answer to the summons he had received, either in obedience to omens which guided him in the prosecution of the affair, as was generally thought, or to repeated warnings conveyed in dreams, he would not come into public or be seen by any one for two days, because he wished to avoid the bissextile day of February which came at that time, and which he knew to have been often an unfortunate day for the Roman empire: of this day I will here give a plain explanation.

Ammianus Marcellinus · translated by C. D. Yonge · 1911 reprint
C. D. Yonge translation (preface dated February 1862); G. Bell and Sons, 1911; Project Gutenberg #28587
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