Check it out:
I just did a search to see how long we took to complete some tasks in WWII.
Some results:
The Battle of Monte Casino -- or more correctly the four battles of Monte Casino -- was the name given to the repeated allied attempts to force the Germans' formidable Gustav Line defences across the width of Italy between Naples and Rome, and which lasted almost five months through the severe winter of 1944 to early May of that year.
Sicily was invaded on 10 July 1943 and by August we were ready to invade Italy.
The result of the first two weeks of the Normandy invasion was a giant foothold for the Allied forces. Two ports were opened to the Allies providing a way for equipment and soldiers to move into France to back up the original Allied force.
D-day for Guadacanal was set for 7 Aug 1942.Fighting continued for the Allies on Guadalcanal into 1943
Just to name a few.