We have to find the year in which the calender of 2023 repeats.
For that ,
divide 2023 with 4
if the reminder is 0 add 28 to the given year
if the reminder is 1 add 6 to the given year
if the reminder is 2 or 3 add 11 to the given year
here the reminder is 3 so on 2034 again the January 1st will on a Sunday