Day of the week related to odd days

Given today is Tuesday, what day of the week was it 200 days ago?

Imagine that in a calendar year, there were 998 days and 12 days in a week, then no.of odd days in that year will be

If the day that will come two days after tomorrow is Thursday, what day of the week was three days before yesterday?

If today is Friday, then what day of the week will be 3 days after tomorrow?

If you were born on March 8, 1990 and the day of the week was a Thursday, then on what day of the week did your birthday fall in 1991?

If 15th August, 2009 is on Saturday, then on which day of the week would the Independence day the celebrated in the year 2109 ?