cpp/chrono/weekday/operator at

@1@ Constructs a std from and. The result represents the -th weekday in some yet-to-be-specified month. If is not in the range [0, 7] or if  the values (an underlying weekday and an index) held in the result are unspecified. @2@ Constructs a std from. The result represents the last weekday in some yet-to-be-specified month.

Return value
@1@ @2@