Systems of ancient weights and measures evolved as needs changed; Solon and other lawgivers also reformed them en bloc.A table of standards derived from theory is as follows:[11] Athenians measured the day by sundials and unit fractions.Periods during night or day were measured by a water clock (clepsydra) that dripped at a steady rate and other methods.In archaic and early classical Greece, months followed the cycle of the Moon which made them not fit exactly into the length of the solar year.Even with this intercalary month, the Athenian or Attic calendar was still fairly inaccurate and days had occasionally to be added by the Archon Basileus.
An obol, Attica, Athens, weighing 0.69g After 449 BC
This section of a frieze from the
Elgin Marbles
shows a cavalry procession that was part of the quadrennial Greater Panathenaic festival, always held in the month Hekatombion.