To change the day in the formula the Bold and underlined number is what requires changing. To change to Thursday, change '1' to '4'.
=A2+(7-WEEKDAY(A2,2)+1)

1 - Monday
2 - Tuesday
3 - Wednesday
4 - Thursday
5 - Friday
6 - Saturday
7 - Sunday

This corresponds with Numbers 1 (Monday) through 7 (Sunday). This is dictated by the number '2' in the formula, changing this number will change the number required to display different days of the week.

=A2+(7-WEEKDAY(A2,2)+1)

Changing '2' will result in the following day changes for '1'

1 or omitted - Numbers 1 (Sunday) through 7 (Saturday)

2 - Numbers 1 (Monday) through 7 (Sunday)

3 - Numbers 0 (Monday) through 6 (Sunday)

11 - Numbers 1 (Monday) through 7 (Sunday)

12 - Numbers 1 (Tuesday) through 7 (Monday)

13 - Numbers 1 (Wednesday) through 7 (Tuesday)

14 - Numbers 1 (Thursday) through 7 (Wednesday)

15 - Numbers 1 (Friday) through 7 (Thursday)

16 - Numbers 1 (Saturday) through 7 (Friday)

17 - Numbers 1 (Sunday) through 7 (Saturday)

Change ",2" to ",5" (Monday is the 2nd day of the week and thus Thursday is the 5th day of the week).