Today's day and date will be given to you. By utilising that you need to find the day of the old date. (Date will be in DD/MM/YYYY format, Consider leap years also).
So here you need to provide output as UnknownDay='Sunday'
Solve the problem in the hypothetical world where 16 April 2019 happens on Saturday instead of Tuesday.
Note: It is not like using "datestr" and finding result. You need to calculate the number of inbetween days and then find the answer.