Answer:
In what year did Christmas Day and New Year's Day fall in the same year?
What ten letter word starts with gas?
What you do to determine the length of something
Often found in doctor's offices and pirate flags
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.