Cf. Aeschines Ctes. 148,
‘ mirrored,’ says Prof. R. B. Richardson ad loc, ‘ in Plut. Dem. 20,
’ Philostratus Vit. Apoll. v 24,
, where the context shews the meaning to be ‘ a small part of a day,’ not ‘a little day,’ Lucian Hermotimus 54, 
where again the meaning is decisively ‘part of a day.’ The Aeschines passage is not quite so clear, but certainly is naturally taken in the same way.