| /* Copyright (c) 2002,2003 CrystalClear Software, Inc. |
| * Use, modification and distribution is subject to the |
| * Boost Software License, Version 1.0. (See accompanying |
| * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt) |
| * Author: Jeff Garland, Bart Garst |
| * $Date: 2010-01-10 14:17:23 -0500 (Sun, 10 Jan 2010) $ |
| */ |
| |
| #ifndef NO_BOOST_DATE_TIME_INLINE |
| #undef BOOST_DATE_TIME_INLINE |
| #define BOOST_DATE_TIME_INLINE inline |
| #endif |
| |
| namespace boost { |
| namespace date_time { |
| //! Return the day of the week (0==Sunday, 1==Monday, etc) |
| /*! Converts a year-month-day into a day of the week number |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| unsigned short |
| gregorian_calendar_base<ymd_type_,date_int_type_>::day_of_week(const ymd_type& ymd) { |
| unsigned short a = static_cast<unsigned short>((14-ymd.month)/12); |
| unsigned short y = static_cast<unsigned short>(ymd.year - a); |
| unsigned short m = static_cast<unsigned short>(ymd.month + 12*a - 2); |
| unsigned short d = static_cast<unsigned short>((ymd.day + y + (y/4) - (y/100) + (y/400) + (31*m)/12) % 7); |
| //std::cout << year << "-" << month << "-" << day << " is day: " << d << "\n"; |
| return d; |
| } |
| |
| //!Return the iso week number for the date |
| /*!Implements the rules associated with the iso 8601 week number. |
| Basically the rule is that Week 1 of the year is the week that contains |
| January 4th or the week that contains the first Thursday in January. |
| Reference for this algorithm is the Calendar FAQ by Claus Tondering, April 2000. |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| int |
| gregorian_calendar_base<ymd_type_,date_int_type_>::week_number(const ymd_type& ymd) { |
| unsigned long julianbegin = julian_day_number(ymd_type(ymd.year,1,1)); |
| unsigned long juliantoday = julian_day_number(ymd); |
| unsigned long day = (julianbegin + 3) % 7; |
| unsigned long week = (juliantoday + day - julianbegin + 4)/7; |
| |
| if ((week >= 1) && (week <= 52)) { |
| return week; |
| } |
| |
| if ((week == 53)) { |
| if((day==6) ||(day == 5 && is_leap_year(ymd.year))) { |
| return week; //under these circumstances week == 53. |
| } else { |
| return 1; //monday - wednesday is in week 1 of next year |
| } |
| } |
| //if the week is not in current year recalculate using the previous year as the beginning year |
| else if (week == 0) { |
| julianbegin = julian_day_number(ymd_type(static_cast<unsigned short>(ymd.year-1),1,1)); |
| juliantoday = julian_day_number(ymd); |
| day = (julianbegin + 3) % 7; |
| week = (juliantoday + day - julianbegin + 4)/7; |
| return week; |
| } |
| |
| return week; //not reachable -- well except if day == 5 and is_leap_year != true |
| |
| } |
| |
| //! Convert a ymd_type into a day number |
| /*! The day number is an absolute number of days since the start of count |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| date_int_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::day_number(const ymd_type& ymd) |
| { |
| unsigned short a = static_cast<unsigned short>((14-ymd.month)/12); |
| unsigned short y = static_cast<unsigned short>(ymd.year + 4800 - a); |
| unsigned short m = static_cast<unsigned short>(ymd.month + 12*a - 3); |
| unsigned long d = ymd.day + ((153*m + 2)/5) + 365*y + (y/4) - (y/100) + (y/400) - 32045; |
| return d; |
| } |
| |
| //! Convert a year-month-day into the julian day number |
| /*! Since this implementation uses julian day internally, this is the same as the day_number. |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| date_int_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::julian_day_number(const ymd_type& ymd) |
| { |
| return day_number(ymd); |
| } |
| |
| //! Convert year-month-day into a modified julian day number |
| /*! The day number is an absolute number of days. |
| * MJD 0 thus started on 17 Nov 1858(Gregorian) at 00:00:00 UTC |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| date_int_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::modjulian_day_number(const ymd_type& ymd) |
| { |
| return julian_day_number(ymd)-2400001; //prerounded |
| } |
| |
| //! Change a day number into a year-month-day |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| ymd_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::from_day_number(date_int_type dayNumber) |
| { |
| date_int_type a = dayNumber + 32044; |
| date_int_type b = (4*a + 3)/146097; |
| date_int_type c = a-((146097*b)/4); |
| date_int_type d = (4*c + 3)/1461; |
| date_int_type e = c - (1461*d)/4; |
| date_int_type m = (5*e + 2)/153; |
| unsigned short day = static_cast<unsigned short>(e - ((153*m + 2)/5) + 1); |
| unsigned short month = static_cast<unsigned short>(m + 3 - 12 * (m/10)); |
| year_type year = static_cast<unsigned short>(100*b + d - 4800 + (m/10)); |
| //std::cout << year << "-" << month << "-" << day << "\n"; |
| |
| return ymd_type(static_cast<unsigned short>(year),month,day); |
| } |
| |
| //! Change a day number into a year-month-day |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| ymd_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::from_julian_day_number(date_int_type dayNumber) |
| { |
| date_int_type a = dayNumber + 32044; |
| date_int_type b = (4*a+3)/146097; |
| date_int_type c = a - ((146097*b)/4); |
| date_int_type d = (4*c + 3)/1461; |
| date_int_type e = c - ((1461*d)/4); |
| date_int_type m = (5*e + 2)/153; |
| unsigned short day = static_cast<unsigned short>(e - ((153*m + 2)/5) + 1); |
| unsigned short month = static_cast<unsigned short>(m + 3 - 12 * (m/10)); |
| year_type year = static_cast<year_type>(100*b + d - 4800 + (m/10)); |
| //std::cout << year << "-" << month << "-" << day << "\n"; |
| |
| return ymd_type(year,month,day); |
| } |
| |
| //! Change a modified julian day number into a year-month-day |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| ymd_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::from_modjulian_day_number(date_int_type dayNumber) { |
| date_int_type jd = dayNumber + 2400001; //is 2400000.5 prerounded |
| return from_julian_day_number(jd); |
| } |
| |
| //! Determine if the provided year is a leap year |
| /*! |
| *@return true if year is a leap year, false otherwise |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| bool |
| gregorian_calendar_base<ymd_type_,date_int_type_>::is_leap_year(year_type year) |
| { |
| //divisible by 4, not if divisible by 100, but true if divisible by 400 |
| return (!(year % 4)) && ((year % 100) || (!(year % 400))); |
| } |
| |
| //! Calculate the last day of the month |
| /*! Find the day which is the end of the month given year and month |
| * No error checking is performed. |
| */ |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| unsigned short |
| gregorian_calendar_base<ymd_type_,date_int_type_>::end_of_month_day(year_type year, |
| month_type month) |
| { |
| switch (month) { |
| case 2: |
| if (is_leap_year(year)) { |
| return 29; |
| } else { |
| return 28; |
| }; |
| case 4: |
| case 6: |
| case 9: |
| case 11: |
| return 30; |
| default: |
| return 31; |
| }; |
| |
| } |
| |
| //! Provide the ymd_type specification for the calandar start |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| ymd_type_ |
| gregorian_calendar_base<ymd_type_,date_int_type_>::epoch() |
| { |
| return ymd_type(1400,1,1); |
| } |
| |
| //! Defines length of a week for week calculations |
| template<typename ymd_type_, typename date_int_type_> |
| BOOST_DATE_TIME_INLINE |
| unsigned short |
| gregorian_calendar_base<ymd_type_,date_int_type_>::days_in_week() |
| { |
| return 7; |
| } |
| |
| |
| } } //namespace gregorian |
| |
| |