I am the first on Earth, the second in Heaven. I appear two times in a week  you can only see me once in a year. Although I am in the middle of the sea, l am not found in month, but l am in February, June, September, October, November & December. What am I? My brother is 4 times as old as I am today. In 5 years time he will be twice as old as I will be. What will my age be in 10 years time?