Number of months with only 30 days
... February only 
has twenty-eight,: And that's just fine,: Except for every fourth year,: When 
February... [DOC] [TLE] Month - Wikipedia [PAR] A month is a unit of time, used with calendars, which is approximately as long as 
a natural ... a 30-day full month followed by a 29-day hollow month  but this is 
only ....