Add inclusion of `<ios>` and `<ctime>` to ensure that the definitions of `std::basic_ios` and `std::tm` are available. As a drive-by fix, change uses of `tm` to `std::tm`. The latter is guaranteed to be available in `<ctime>`, but the former isn't.
Add inclusion of `<ios>` and `<ctime>` to ensure that the definitions of `std::basic_ios` and `std::tm` are available. As a drive-by fix, change uses of `tm` to `std::tm`. The latter is guaranteed to be available in `<ctime>`, but the former isn't.