Well, yes. April 6 April 30, 1941.
The Italians and Bulgarians helped.
The Italians never made it into Greece. The Greeks spanked them in Albania and forced hitler to use real troops to take Greece. Thousands of the Greek soldiers and military commanders fled as a result of the nazi invasion. The only group to make a determined stand against the nazis, were the Cretians. The follow on Greek resistance movements ended up fighting themselves more so than the nazi occupiers.
I suppose if the Greeks want to claim some sort of military prowess, they could argue that they held out longer than France did.