Function seconds

util/datetime/base.h:48–50

const int DATE_BUF_LEN = 4 + 2 + 2 + 1; // [YYYYMMDD*]

constexpr long seconds(const struct tm& theTm) {
    return 60 * (60 * theTm.tm_hour + theTm.tm_min) + theTm.tm_sec;
}

void sprint_gm_date(char* buf, time_t when, long* sec = nullptr);
bool sscan_date(const char* date, struct tm& theTm);