How can I calculate anniversary date (10, 20, 30, 40, 50, and etc.) ?

turan_aghayev 

This may be totally unnecessary but it was fun creating.  I put all the dates in the one column because it seems you may have preferred that to multiple columns.

=LAMBDA(birth_days,number_of_anniversaries,BYROW(
    birth_days,
    LAMBDA(row,
        TEXTJOIN(
            ", ",
            ,
            TEXT(
                DATE(YEAR(row) + SEQUENCE(, number_of_anniversaries, 10, 10), MONTH(row), DAY(row)),
                "m/d/yyy"
            )
        )
    )
))

The Anniversary function.  Provide the birthdays and tell it how many anniversaries you'd like to show:

=Anniversary(bday,5)

turan_aghayev 

Or

=EDATE($B2,12*C$1)

turan_aghayev 

See the attached file for your answer. It looks like this, using this formula copied from cell C2 to all the others. =DATE(YEAR($B2)+C$1,MONTH($B2),DAY($B2))