Package org.orekit.time

Class DateComponents

  • All Implemented Interfaces:
    Serializable, Comparable<DateComponents>
    public class DateComponents
extends Object
implements Serializable, Comparable<DateComponents>
    Class representing a date broken up as year, month and day components.

    This class uses the astronomical convention for calendars, which is also the convention used by java.util.Date: a year zero is present between years -1 and +1, and 10 days are missing in 1582. The calendar used around these special dates are:

    • up to 0000-12-31 : proleptic julian calendar
    • from 0001-01-01 to 1582-10-04: julian calendar
    • from 1582-10-15: gregorian calendar

    Instances of this class are guaranteed to be immutable.

    Author:
    Luc Maisonobe
    See Also:
    TimeComponents, DateTimeComponents, Serialized Form

    • Field Detail

      • JULIAN_EPOCH

        public static final DateComponents JULIAN_EPOCH
        Reference epoch for julian dates: -4712-01-01.

        Both java.util.Date and DateComponents classes follow the astronomical conventions and consider a year 0 between years -1 and +1, hence this reference date lies in year -4712 and not in year -4713 as can be seen in other documents or programs that obey a different convention (for example the convcal utility).

      • MODIFIED_JULIAN_EPOCH

        public static final DateComponents MODIFIED_JULIAN_EPOCH
        Reference epoch for modified julian dates: 1858-11-17.

      • FIFTIES_EPOCH

        public static final DateComponents FIFTIES_EPOCH
        Reference epoch for 1950 dates: 1950-01-01.

      • CCSDS_EPOCH

        public static final DateComponents CCSDS_EPOCH
        Reference epoch for CCSDS Time Code Format (CCSDS 301.0-B-4): 1958-01-01.

      • GALILEO_EPOCH

        public static final DateComponents GALILEO_EPOCH
        Reference epoch for Galileo System Time: 1999-08-22.

      • GPS_EPOCH

        public static final DateComponents GPS_EPOCH
        Reference epoch for GPS weeks: 1980-01-06.

      • J2000_EPOCH

        public static final DateComponents J2000_EPOCH
        J2000.0 Reference epoch: 2000-01-01.

      • JAVA_EPOCH

        public static final DateComponents JAVA_EPOCH
        Java Reference epoch: 1970-01-01.

      • MAX_EPOCH

        public static final DateComponents MAX_EPOCH
        Maximum supported date.

        This is date 5881610-07-11 which corresponds to Integer.MAX_VALUE days after J2000_EPOCH.

        Since:
        9.0

      • MIN_EPOCH

        public static final DateComponents MIN_EPOCH
        Maximum supported date.

        This is date -5877490-03-03, which corresponds to Integer.MIN_VALUE days before J2000_EPOCH.

        Since:
        9.0

    • Constructor Detail

      • DateComponents

        public DateComponents​(int year,
                      int month,
                      int day)
               throws IllegalArgumentException
        Build a date from its components.
        Parameters:
        year - year number (may be 0 or negative for BC years)
        month - month number from 1 to 12
        day - day number from 1 to 31
        Throws:
        IllegalArgumentException - if inconsistent arguments are given (parameters out of range, february 29 for non-leap years, dates during the gregorian leap in 1582 ...)

      • DateComponents

        public DateComponents​(int year,
                      Month month,
                      int day)
               throws IllegalArgumentException
        Build a date from its components.
        Parameters:
        year - year number (may be 0 or negative for BC years)
        month - month enumerate
        day - day number from 1 to 31
        Throws:
        IllegalArgumentException - if inconsistent arguments are given (parameters out of range, february 29 for non-leap years, dates during the gregorian leap in 1582 ...)

      • DateComponents

        public DateComponents​(int year,
                      int dayNumber)
               throws IllegalArgumentException
        Build a date from a year and day number.
        Parameters:
        year - year number (may be 0 or negative for BC years)
        dayNumber - day number in the year from 1 to 366
        Throws:
        IllegalArgumentException - if dayNumber is out of range with respect to year

      • DateComponents

        public DateComponents​(int offset)
        Build a date from its offset with respect to a J2000_EPOCH.
        Parameters:
        offset - offset with respect to a J2000_EPOCH
        See Also:
        getJ2000Day()

      • DateComponents

        public DateComponents​(DateComponents epoch,
                      int offset)
        Build a date from its offset with respect to a reference epoch.

        This constructor is mainly useful to build a date from a modified julian day (using MODIFIED_JULIAN_EPOCH) or a GPS week number (using GPS_EPOCH).

        Parameters:
        epoch - reference epoch
        offset - offset with respect to a reference epoch
        See Also:
        DateComponents(int), getMJD()

    • Method Detail

      • createFromWeekComponents

        public static DateComponents createFromWeekComponents​(int wYear,
                                                      int week,
                                                      int dayOfWeek)
                                               throws IllegalArgumentException
        Build a date from week components.

        The calendar week number is a number between 1 and 52 or 53 depending on the year. Week 1 is defined by ISO as the one that includes the first Thursday of a year. Week 1 may therefore start the previous year and week 52 or 53 may end in the next year. As an example calendar date 1995-01-01 corresponds to week date 1994-W52-7 (i.e. Sunday in the last week of 1994 is in fact the first day of year 1995). This date would beAnother example is calendar date 1996-12-31 which corresponds to week date 1997-W01-2 (i.e. Tuesday in the first week of 1997 is in fact the last day of year 1996).

        Parameters:
        wYear - year associated to week numbering
        week - week number in year, from 1 to 52 or 53
        dayOfWeek - day of week, from 1 (Monday) to 7 (Sunday)
        Returns:
        a builded date
        Throws:
        IllegalArgumentException - if inconsistent arguments are given (parameters out of range, week 53 on a 52 weeks year ...)

      • parseDate

        public static DateComponents parseDate​(String string)
        Parse a string in ISO-8601 format to build a date.

        The supported formats are:

        • basic format calendar date: YYYYMMDD
        • extended format calendar date: YYYY-MM-DD
        • basic format ordinal date: YYYYDDD
        • extended format ordinal date: YYYY-DDD
        • basic format week date: YYYYWwwD
        • extended format week date: YYYY-Www-D

        As shown by the list above, only the complete representations defined in section 4.1 of ISO-8601 standard are supported, neither expended representations nor representations with reduced accuracy are supported.

        Parsing a single integer as a julian day is not supported as it may be ambiguous with either the basic format calendar date or the basic format ordinal date depending on the number of digits.

        Parameters:
        string - string to parse
        Returns:
        a parsed date
        Throws:
        IllegalArgumentException - if string cannot be parsed

      • getYear

        public int getYear()
        Get the year number.
        Returns:
        year number (may be 0 or negative for BC years)

      • getMonth

        public int getMonth()
        Get the month.
        Returns:
        month number from 1 to 12

      • getMonthEnum

        public Month getMonthEnum()
        Get the month as an enumerate.
        Returns:
        month as an enumerate

      • getDay

        public int getDay()
        Get the day.
        Returns:
        day number from 1 to 31

      • getJ2000Day

        public int getJ2000Day()
        Get the day number with respect to J2000 epoch.
        Returns:
        day number with respect to J2000 epoch

      • getMJD

        public int getMJD()
        Get the modified julian day.
        Returns:
        modified julian day

      • getCalendarWeek

        public int getCalendarWeek()
        Get the calendar week number.

        The calendar week number is a number between 1 and 52 or 53 depending on the year. Week 1 is defined by ISO as the one that includes the first Thursday of a year. Week 1 may therefore start the previous year and week 52 or 53 may end in the next year. As an example calendar date 1995-01-01 corresponds to week date 1994-W52-7 (i.e. Sunday in the last week of 1994 is in fact the first day of year 1995). Another example is calendar date 1996-12-31 which corresponds to week date 1997-W01-2 (i.e. Tuesday in the first week of 1997 is in fact the last day of year 1996).

        Returns:
        calendar week number

      • getDayOfWeek

        public int getDayOfWeek()
        Get the day of week.

        Day of week is a number between 1 (Monday) and 7 (Sunday).

        Returns:
        day of week

      • getDayOfYear

        public int getDayOfYear()
        Get the day number in year.

        Day number in year is between 1 (January 1st) and either 365 or 366 inclusive depending on year.

        Returns:
        day number in year

      • toString

        public String toString()
        Get a string representation (ISO-8601) of the date.
        Overrides:
        toString in class Object
        Returns:
        string representation of the date.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object