Class Datetime

inst/include/Rcpp/date_datetime/Datetime.h:33–120

namespace Rcpp {

    class Datetime {
    public:
        Datetime() {
            m_dt = 0;
            update_tm();
        }
        Datetime(SEXP s);

        // from double, just like POSIXct
        Datetime(const double &dt) {
            m_dt = dt;
            update_tm();
        }
        Datetime(const std::string &s, const std::string &fmt="%Y-%m-%d %H:%M:%OS");

        double getFractionalTimestamp(void) const { return m_dt; }

        int getMicroSeconds() const { return m_us; }
        int getSeconds()      const { return m_tm.tm_sec; }
        int getMinutes()      const { return m_tm.tm_min; }
        int getHours()        const { return m_tm.tm_hour; }
        int getDay()          const { return m_tm.tm_mday; }
        int getMonth()        const { return m_tm.tm_mon + 1; }      // makes it 1 .. 12
        int getYear()         const { return m_tm.tm_year ; }
        int getWeekday()      const { return m_tm.tm_wday + 1; }     // makes it 1 .. 7
        int getYearday()      const { return m_tm.tm_yday + 1; }     // makes it 1 .. 366

        // Minimal set of date operations.
        friend Datetime  operator+( const Datetime &dt, double offset);
        friend Datetime  operator+( const Datetime &dt, int offset);
        friend double    operator-( const Datetime &dt1, const Datetime& dt2);
        friend bool      operator<( const Datetime &dt1, const Datetime& dt2);
        friend bool      operator>( const Datetime &dt1, const Datetime& dt2);
        friend bool      operator==(const Datetime &dt1, const Datetime& dt2);
        friend bool      operator>=(const Datetime &dt1, const Datetime& dt2);
        friend bool      operator<=(const Datetime &dt1, const Datetime& dt2);
        friend bool      operator!=(const Datetime &dt1, const Datetime& dt2);

        inline int is_na() const { return traits::is_na<REALSXP>(m_dt); }

        operator double()  const { return m_dt; }

        inline std::string format(const char *fmt = "%Y-%m-%d %H:%M:%S") const {
            char txtiso[64], txtsec[64];
            time_t t = static_cast<time_t>(std::floor(m_dt));
            struct tm temp = *localtime(&t); // localtime, not gmtime
            size_t res = ::strftime(txtiso, 63, fmt, &temp);
            if (res == 0) {
                return std::string("");
            } else {
                res = ::snprintf(txtsec, 63, "%s.%06d", txtiso, m_us);
                if (res <= 0) {
                    return std::string("");
                } else {
                    return std::string(txtsec);
                }
            }
        }