Here, we have given a date along with the day and we need to find out the day of the next date given.

For, 28 Feb 2020 was Friday

Since, 2019, 2018, 2017 are ordinary years. All have only 1 odd day.

And, 2016 is a leap year. This will have 2 odd days.

Total days = 1 + 1 + 1 + 2 = 5.

So, 28 Feb 2016 = Friday - 5 = Sunday

Next, we will count the days of the remaining months as:

27 (Feb) + 31 (Jan) + 2 (Dec) = 60 = 8 weeks and 4 odd days.

Thus, 30 Dec 2015 was Sunday - 4 = Wednesday.

Hence, it was '**Wednesday**' on 30 Dec 2015.