Question: On what day did Germany invide both Yugoslavia and Greece during World War II?
About the article "World War II", section "Mediterranean (1940–41)".

Candidate passages:
During World War II, Operation Marita was the German invasion of Greece and Yugoslavia on 6 April 1941. 
During World War II, Slovenia was in a unique situation.
While Greece shared its experience of being trisected, Slovenia was the only country that experienced a further step—absorption and annexation into neighboring Nazi Germany, Fascist Italy, and Hungary.
After Yugoslavia was invaded by Axis Powers on 6 April 1941, Germany and Hungary occupied northern Slovenia.
The ethnic German Gottscheers were moved out of the province because Hitler opposed having them in the Italian occupation zone.  
The Balkan Campaign of World War II began with the Italian invasion of Greece on 28 October 1940.
In the early months of 1941, Italy's offensive had been stalled and a Greek counter-offensive pushed into Albania.
Germany sought, by deploying troops to Romania and Bulgaria, to aid Italy by attacking Greece from the east; while the British landed troops and aircraft to shore up Greek defences.
A "coup d'état" in Yugoslavia on 27 March caused Hitler to order the conquest of that country.
The invasion of Yugoslavia by Germany and Italy began on 6 April, simultaneously with the new Battle of Greece.
On 11 April, Hungary joined the invasion.
By 17 April the Yugoslavs had signed an armistice and by 30 April all of mainland Greece was under German or Italian control.
On 20 May Germany invaded Crete by air and by 1 June all remaining Greek and British forces on the island had surrendered.
Although it had not participated in the attacks in April, Bulgaria occupied parts of both Yugoslavia and Greece shortly thereafter for the remainder of the war in the Balkans. 
By 1 June 1941, all of Albania, Yugoslavia and Greece were under Axis control.
Greece was placed under triple occupation, and Yugoslavia was dissolved and occupied.
Germany had gained a significant strategic advantage: direct access to the Mediterranean.
The Allied High Command feared that Crete and Greece would be used as "springboard" for an invasion of British Egypt or Cyprus.
However, any plans for a large-scale invasion of Egypt and Palestine were abandoned when Operation Barbarossa commenced on 22 June.
The effect of the Balkans Campaign on the outcome of Operation Barbarossa is still debated to this day. 
On 6 April 1941, despite having officially joined the Axis Powers, the Bulgarian government did not participate in the invasion of Yugoslavia and the Battle of Greece.
As German, Italian, and Hungarian troops crushed Yugoslavia and Greece, the Bulgarians remained on the side-lines.
The Yugoslav government surrendered on 17 April.
The Greek government was to hold out until 30 April.
On 20 April, the Bulgarian Army occupied most of Western Thrace and the Greek province of Eastern Macedonia, which had been already conquered by Germany, with the goal of restoring its pre-World War I outlet to the Aegean Sea.
Bulgarian troops also occupied much of eastern Serbia, where the so-called Vardar Banovina was divided between Bulgaria and the Italians.