Source : Webster's Revised Unabridged Dictionary (1913)

Datable \Dat"a*ble\, a.
   That may be dated; having a known or ascertainable date.
   ``Datable almost to a year.'' --The Century.

Source : WordNet®

datable
     adj : that can be given a date; "a concrete and datable
           happening"- C.W.Shumaker [syn: {dateable}] [ant: {undatable}]