I am something, I appear first on earth, second in heaven. I appear twice in a week, Never in a month, but I appear once in a year what am I?

It's one of the letters of the alphabet. Do you see which one?

ITS E

To determine the answer to this riddle, we can break down the information provided and analyze each clue.

1. "I am something": This tells us that the answer is a specific thing or object.
2. "I appear first on earth, second in heaven": This suggests that the thing being referred to has a different order of appearance on Earth and in heaven.
3. "I appear twice in a week": This clue tells us that the thing in question shows up two times during a week, indicating a repeating pattern.
4. "Never in a month": Here, the riddle states that the thing does not appear at all within a month, meaning it is absent for the duration of a month.
5. "I appear once in a year": This implies that the thing only shows up once within a year, indicating an annual occurrence.

By carefully considering all of these clues, we can deduce that the answer to this riddle is the letter "E". It satisfies all the conditions stated in the riddle: the letter "E" appears first in the word "Earth" and second in the word "Heaven", it occurs twice in the word "week" (appearing at the beginning and end), it is not present in the word "month", and it appears once in the word "year".