Answer:
In a year, there are 12 months. Seven months have 31 days. How many months have 28 days?
I am a king but also a common device of measure. What am I?
Longer than a decade and shorter than a milennium
If there are three cups of sugar and you take one away, how many do you have?
Retired people want these to be large and birds want them to hatch.
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.