If it is Friday on January 1, 1998, then January 1, 2000 would have been :

Monday Wednesday Friday Sunday

Sunday

If the date and the month is same then we will check the difference between the years and then simply add in the given day. Given, it is Friday on January 1, 1998 we have to find = January 1, 2000 There is a difference between 2000 - 1998 = 2 years. So the day on January 1, 2000 will be =  Friday + 2 = Sunday