41 #include "boost/format.hpp" 42 #include "boost/regex.hpp" 54 static double const MJD_TO_JD = 2400000.5;
55 static double const EPOCH_IN_MJD = 40587.0;
56 static double const JD2000 = 2451544.50;
59 static double const NSEC_PER_DAY = 86.4e12;
62 static long long const LL_NSEC_PER_SEC = 1000000000LL;
70 static double const MAX_DAYS = 106751.99;
74 static double const HOURS_PER_DAY = 24.0;
75 static double const MIN_PER_DAY = 1440.0;
76 static double const SEC_PER_DAY = 86400.0;
80 static long long const TT_MINUS_TAI_NSECS = 32184000000LL;
88 1961 JAN 1 =JD 2437300.5 TAI-UTC= 1.4228180 S + (MJD - 37300.) X 0.001296 S\n\ 89 1961 AUG 1 =JD 2437512.5 TAI-UTC= 1.3728180 S + (MJD - 37300.) X 0.001296 S\n\ 90 1962 JAN 1 =JD 2437665.5 TAI-UTC= 1.8458580 S + (MJD - 37665.) X 0.0011232S\n\ 91 1963 NOV 1 =JD 2438334.5 TAI-UTC= 1.9458580 S + (MJD - 37665.) X 0.0011232S\n\ 92 1964 JAN 1 =JD 2438395.5 TAI-UTC= 3.2401300 S + (MJD - 38761.) X 0.001296 S\n\ 93 1964 APR 1 =JD 2438486.5 TAI-UTC= 3.3401300 S + (MJD - 38761.) X 0.001296 S\n\ 94 1964 SEP 1 =JD 2438639.5 TAI-UTC= 3.4401300 S + (MJD - 38761.) X 0.001296 S\n\ 95 1965 JAN 1 =JD 2438761.5 TAI-UTC= 3.5401300 S + (MJD - 38761.) X 0.001296 S\n\ 96 1965 MAR 1 =JD 2438820.5 TAI-UTC= 3.6401300 S + (MJD - 38761.) X 0.001296 S\n\ 97 1965 JUL 1 =JD 2438942.5 TAI-UTC= 3.7401300 S + (MJD - 38761.) X 0.001296 S\n\ 98 1965 SEP 1 =JD 2439004.5 TAI-UTC= 3.8401300 S + (MJD - 38761.) X 0.001296 S\n\ 99 1966 JAN 1 =JD 2439126.5 TAI-UTC= 4.3131700 S + (MJD - 39126.) X 0.002592 S\n\ 100 1968 FEB 1 =JD 2439887.5 TAI-UTC= 4.2131700 S + (MJD - 39126.) X 0.002592 S\n\ 101 1972 JAN 1 =JD 2441317.5 TAI-UTC= 10.0 S + (MJD - 41317.) X 0.0 S\n\ 102 1972 JUL 1 =JD 2441499.5 TAI-UTC= 11.0 S + (MJD - 41317.) X 0.0 S\n\ 103 1973 JAN 1 =JD 2441683.5 TAI-UTC= 12.0 S + (MJD - 41317.) X 0.0 S\n\ 104 1974 JAN 1 =JD 2442048.5 TAI-UTC= 13.0 S + (MJD - 41317.) X 0.0 S\n\ 105 1975 JAN 1 =JD 2442413.5 TAI-UTC= 14.0 S + (MJD - 41317.) X 0.0 S\n\ 106 1976 JAN 1 =JD 2442778.5 TAI-UTC= 15.0 S + (MJD - 41317.) X 0.0 S\n\ 107 1977 JAN 1 =JD 2443144.5 TAI-UTC= 16.0 S + (MJD - 41317.) X 0.0 S\n\ 108 1978 JAN 1 =JD 2443509.5 TAI-UTC= 17.0 S + (MJD - 41317.) X 0.0 S\n\ 109 1979 JAN 1 =JD 2443874.5 TAI-UTC= 18.0 S + (MJD - 41317.) X 0.0 S\n\ 110 1980 JAN 1 =JD 2444239.5 TAI-UTC= 19.0 S + (MJD - 41317.) X 0.0 S\n\ 111 1981 JUL 1 =JD 2444786.5 TAI-UTC= 20.0 S + (MJD - 41317.) X 0.0 S\n\ 112 1982 JUL 1 =JD 2445151.5 TAI-UTC= 21.0 S + (MJD - 41317.) X 0.0 S\n\ 113 1983 JUL 1 =JD 2445516.5 TAI-UTC= 22.0 S + (MJD - 41317.) X 0.0 S\n\ 114 1985 JUL 1 =JD 2446247.5 TAI-UTC= 23.0 S + (MJD - 41317.) X 0.0 S\n\ 115 1988 JAN 1 =JD 2447161.5 TAI-UTC= 24.0 S + (MJD - 41317.) X 0.0 S\n\ 116 1990 JAN 1 =JD 2447892.5 TAI-UTC= 25.0 S + (MJD - 41317.) X 0.0 S\n\ 117 1991 JAN 1 =JD 2448257.5 TAI-UTC= 26.0 S + (MJD - 41317.) X 0.0 S\n\ 118 1992 JUL 1 =JD 2448804.5 TAI-UTC= 27.0 S + (MJD - 41317.) X 0.0 S\n\ 119 1993 JUL 1 =JD 2449169.5 TAI-UTC= 28.0 S + (MJD - 41317.) X 0.0 S\n\ 120 1994 JUL 1 =JD 2449534.5 TAI-UTC= 29.0 S + (MJD - 41317.) X 0.0 S\n\ 121 1996 JAN 1 =JD 2450083.5 TAI-UTC= 30.0 S + (MJD - 41317.) X 0.0 S\n\ 122 1997 JUL 1 =JD 2450630.5 TAI-UTC= 31.0 S + (MJD - 41317.) X 0.0 S\n\ 123 1999 JAN 1 =JD 2451179.5 TAI-UTC= 32.0 S + (MJD - 41317.) X 0.0 S\n\ 124 2006 JAN 1 =JD 2453736.5 TAI-UTC= 33.0 S + (MJD - 41317.) X 0.0 S\n\ 125 2009 JAN 1 =JD 2454832.5 TAI-UTC= 34.0 S + (MJD - 41317.) X 0.0 S\n\ 126 2012 JUL 1 =JD 2456109.5 TAI-UTC= 35.0 S + (MJD - 41317.) X 0.0 S\n\ 127 2015 JUL 1 =JD 2457204.5 TAI-UTC= 36.0 S + (MJD - 41317.) X 0.0 S\n\ 128 2017 JAN 1 =JD 2457754.5 TAI-UTC= 37.0 S + (MJD - 41317.) X 0.0 S\n\ 149 LeapTable leapSecTable;
151 LeapTable::LeapTable(
void) {
161 template<
typename NsType>
162 NsType utcToTai(NsType nsecs) {
164 for (i = 0; i < leapSecTable.size(); ++i) {
165 if (nsecs < leapSecTable[i].whenUtc)
break;
171 "DateTime value too early for UTC-TAI conversion: %1%" 174 Leap
const& l(leapSecTable[i - 1]);
175 double mjd =
static_cast<double>(nsecs) / NSEC_PER_DAY + EPOCH_IN_MJD;
176 double leapSecs = l.offset + (mjd - l.mjdRef) * l.drift;
177 NsType leapNSecs = static_cast<NsType>(leapSecs * 1.0e9 + 0.5);
178 return nsecs + leapNSecs;
187 template<
typename NsType>
188 NsType taiToUtc(NsType nsecs) {
190 for (i = 0; i < leapSecTable.size(); ++i) {
191 if (nsecs < leapSecTable[i].whenTai)
break;
197 "DateTime value too early for TAI-UTC conversion: %1%" 200 Leap
const& l(leapSecTable[i - 1]);
201 double mjd =
static_cast<double>(nsecs) / NSEC_PER_DAY + EPOCH_IN_MJD;
202 double leapSecs = l.offset + (mjd - l.mjdRef) * l.drift;
204 leapSecs /= 1.0 + l.drift * 1.0e9 / NSEC_PER_DAY;
205 NsType leapNSecs = static_cast<NsType>(leapSecs * 1.0e9 + 0.5);
206 return nsecs - leapNSecs;
221 return nsecs - TT_MINUS_TAI_NSECS;
223 return utcToTai(nsecs);
226 os <<
"Unsupported scale " << scale;
242 return nsecs + TT_MINUS_TAI_NSECS;
244 return taiToUtc(nsecs);
247 os <<
"Unsupported scale " << scale;
264 double calendarToJd(
int year,
int month,
int day,
int hour,
int min,
double sec) {
269 int a = int(year/100);
270 int b = 2 - a + int(a/4);
272 int yy = 1582, mm = 10;
273 if (year < yy || (year == yy && month < mm) || (year == yy && month == mm && day <= 4)) {
277 double jd =
static_cast<int>(365.25*(year + 4716)) +
278 static_cast<int>(30.6001*(month + 1)) + day + b - 1524.5;
279 jd += hour/HOURS_PER_DAY + min/MIN_PER_DAY + sec/SEC_PER_DAY;
292 void DateTime::setNsecsFromMjd(
double mjd, Timescale scale) {
294 if (mjd > EPOCH_IN_MJD + MAX_DAYS) {
297 (boost::format(
"MJD too far in the future: %1%") % mjd).str());
299 if (mjd < EPOCH_IN_MJD - MAX_DAYS) {
302 (boost::format(
"MJD too far in the past: %1%") % mjd).str());
304 _nsecs = nsecAnyToTai(static_cast<long long>((mjd - EPOCH_IN_MJD) * NSEC_PER_DAY), scale);
307 void DateTime::setNsecsFromJd(
double jd, Timescale scale) {
308 setNsecsFromMjd(jd - MJD_TO_JD, scale);
316 void DateTime::setNsecsFromEpoch(
double epoch, Timescale scale) {
317 setNsecsFromMjd(365.25*(epoch - 2000.0) + JD2000 - MJD_TO_JD, scale);
320 DateTime::DateTime() :
325 _nsecs(nsecAnyToTai(nsecs, scale))
331 setNsecsFromMjd(date, scale);
334 setNsecsFromJd(date, scale);
337 setNsecsFromEpoch(date, scale);
346 int const minYear = 1902;
347 int const maxYear = 2261;
348 if ((year < minYear) || (year > maxYear)) {
351 (boost::format(
"Year = %d out of range [%04d, %04d]") % year % minYear % maxYear).str());
355 tm.tm_year = year - 1900;
356 tm.tm_mon = month - 1;
370 time_t secs = timegm(&tm);
388 if (timegm(&tm) != -1) {
395 (boost::format(
"Unconvertible date: %04d-%02d-%02dT%02d:%02d:%02d")
396 % year % month % day % hr % min % sec).str());
400 _nsecs = nsecAnyToTai(secs * LL_NSEC_PER_SEC, scale);
407 re = boost::regex(
"(\\d{4})-?(\\d{2})-?(\\d{2})" "T" 408 "(\\d{2}):?(\\d{2}):?(\\d{2})" "([.,](\\d*))?" "Z");
411 re = boost::regex(
"(\\d{4})-?(\\d{2})-?(\\d{2})" "T" 412 "(\\d{2}):?(\\d{2}):?(\\d{2})" "([.,](\\d*))?");
414 boost::smatch matches;
415 if (!regex_match(iso8601, matches, re)) {
417 "Not in acceptable ISO8601 format: " + iso8601);
421 DateTime dt(atoi(matches.str(1).c_str()), atoi(matches.str(2).c_str()),
422 atoi(matches.str(3).c_str()), atoi(matches.str(4).c_str()),
423 atoi(matches.str(5).c_str()), atoi(matches.str(6).c_str()),
427 if (matches[7].matched) {
429 int places = frac.
size();
433 int value = atoi(frac.
c_str());
446 return _getMjd(scale);
449 return _getJd(scale);
452 return _getEpoch(scale);
465 return nsecTaiToAny(_nsecs, scale);
468 double DateTime::_getMjd(
Timescale scale)
const {
470 double nsecs = nsecTaiToAny(_nsecs, scale);
471 return nsecs / NSEC_PER_DAY + EPOCH_IN_MJD;
474 double DateTime::_getJd(
Timescale scale)
const {
475 return _getMjd(scale) + MJD_TO_JD;
478 double DateTime::_getEpoch(
Timescale scale)
const {
479 return 2000.0 + (_getJd(scale) - JD2000)/365.25;
485 long long nsecs = nsecTaiToAny(_nsecs, scale);
487 long long frac = nsecs % LL_NSEC_PER_SEC;
488 if (nsecs < 0 && frac < 0) {
489 nsecs -= LL_NSEC_PER_SEC + frac;
494 time_t secs =
static_cast<time_t
>(nsecs / LL_NSEC_PER_SEC);
495 gmtime_r(&secs, &gmt);
502 long long nsecs = nsecTaiToAny(_nsecs, scale);
503 ts.tv_sec =
static_cast<time_t
>(nsecs / LL_NSEC_PER_SEC);
504 ts.tv_nsec =
static_cast<int>(nsecs % LL_NSEC_PER_SEC);
511 long long nsecs = nsecTaiToAny(_nsecs, scale);
512 tv.tv_sec =
static_cast<time_t
>(nsecs / LL_NSEC_PER_SEC);
513 tv.tv_usec =
static_cast<int>((nsecs % LL_NSEC_PER_SEC) / 1000);
519 struct tm gmt(this->gmtime(scale));
521 long long fracnsecs = nsecTaiToAny(_nsecs, scale) % LL_NSEC_PER_SEC;
523 fracnsecs += LL_NSEC_PER_SEC;
525 auto fmtStr = scale ==
UTC ?
"%04d-%02d-%02dT%02d:%02d:%02d.%09dZ" 526 :
"%04d-%02d-%02dT%02d:%02d:%02d.%09d";
527 return (boost::format(fmtStr) %
528 (gmt.tm_year + 1900) % (gmt.tm_mon + 1) % gmt.tm_mday %
529 gmt.tm_hour % gmt.tm_min % gmt.tm_sec % fracnsecs).str();
533 return _nsecs == rhs._nsecs;
538 int ret = gettimeofday(&tv, 0);
541 "Unable to get current time");
543 long long nsecs = tv.tv_sec * LL_NSEC_PER_SEC + tv.tv_usec * 1000LL;
549 leapSecTable.clear();
550 boost::regex re(
"^\\d{4}.*?=JD\\s*([\\d.]+)\\s+TAI-UTC=\\s+([\\d.]+)\\s+S" 551 " \\+ \\(MJD - ([\\d.]+)\\) X ([\\d.]+)\\s*S$");
552 for (boost::cregex_iterator i = make_regex_iterator(leapString.
c_str(), re);
553 i != boost::cregex_iterator(); ++i) {
554 double mjdUtc = strtod((*i)[1].first, 0) - MJD_TO_JD;
555 l.offset = strtod((*i)[2].first, 0);
556 l.mjdRef = strtod((*i)[3].first, 0);
557 l.drift = strtod((*i)[4].first, 0);
558 l.whenUtc =
static_cast<long long>(
559 (mjdUtc - EPOCH_IN_MJD) * NSEC_PER_DAY);
560 l.whenTai = l.whenUtc +
static_cast<long long>(
561 1.0e9 * (l.offset + (mjdUtc - l.mjdRef) * l.drift));
562 leapSecTable.push_back(l);
struct timespec timespec(Timescale scale) const
Get date as a timespec struct, with time in seconds and nanoseconds.
double get(DateSystem system=MJD, Timescale scale=TAI) const
Get date as a double in a specified representation, such as MJD.
Class for handling dates/times, including MJD, UTC, and TAI.
struct tm gmtime(Timescale scale) const
Get date as a tm struct, with truncated fractional seconds.
static void initializeLeapSeconds(std::string const &leapString)
Initialize the leap second table from USNO.
std::string toString(Timescale scale) const
Get date as an ISO8601-formatted string.
bool operator==(DateTime const &rhs) const
struct timeval timeval(Timescale scale) const
Get date as a timeval struct, with time in seconds and microseconds.
static DateTime now(void)
Return current time as a DateTime.
long long nsecs(Timescale scale=TAI) const
Get date as nanoseconds since the unix epoch.
Interface for DateTime class.
#define LSST_EXCEPT(type,...)
bool isValid() const
Is this date valid?
static constexpr long long invalid_nsecs
DateTime()
Default constructor: construct an invalid DateTime.