the letter "e"
The letter 'S'. Saturday and Sunday come twice a week and September comes once a year..
The letter 'e'
e
The letter 'e'. It appears once in year, twice in week and never in day.
The letter 'e'. It appears once in year, twice in week and never in day.
The letter E appears twice in the word "week" and only once in the word "year."
The letter "e"
The letter E
The letter E
The letter E appears twice in the word "week" and only once in the word "year."
The letter "e"
The answer to this riddle is the letter "W". The letter "W" appears twice in a week (Monday and Wednesday) and once in a while (as in "once in a while"), but it never appears in a month because there is no "W" in the names of the months of the year.