Older than anything in that thread are Bosporan staters, like
this one, and Western Kshatrap coins, like
this one*.
Even further back, Seleukid coins often had dates on them (I have one from the 2nd century BC - though it's not on Numista).
Supposedly the world's oldest known dated coins are from the siege of Zankle (now Messina in Sicily) - dated first year of the siege, second year, third year, fourth year...
I forgot what it comes out to in the normal calendar (somewhere 5th century BC).
*) presumably they're listed as ND because it's actually fairly uncommon for one of those coins to have a visible date - usually it's off flan
