Package org.xlsx4j.org.apache.poi.ss.usermodel

Class DateUtil

java.lang.Object
org.xlsx4j.org.apache.poi.ss.usermodel.DateUtil
public class DateUtil extends Object
Contains methods for dealing with Excel dates.

  • Field Details

  • Constructor Details

    • DateUtil

      protected DateUtil()

  • Method Details

    • getExcelDate

      public static double getExcelDate(Date date)
      Given a Date, converts it into a double representing its internal Excel representation, which is the number of days since 1/1/1900. Fractional days represent hours, minutes, and seconds.
      Parameters:
      date - the Date
      Returns:
      Excel representation of Date (-1 if error - test for error by checking for less than 0.1)

    • getExcelDate

      public static double getExcelDate(Date date, boolean use1904windowing)
      Given a Date, converts it into a double representing its internal Excel representation, which is the number of days since 1/1/1900. Fractional days represent hours, minutes, and seconds.
      Parameters:
      date - the Date
      use1904windowing - Should 1900 or 1904 date windowing be used?
      Returns:
      Excel representation of Date (-1 if error - test for error by checking for less than 0.1)

    • getExcelDate

      public static double getExcelDate(Calendar date, boolean use1904windowing)
      Given a Date in the form of a Calendar, converts it into a double representing its internal Excel representation, which is the number of days since 1/1/1900. Fractional days represent hours, minutes, and seconds.
      Parameters:
      date - the Calendar holding the date to convert
      use1904windowing - Should 1900 or 1904 date windowing be used?
      Returns:
      Excel representation of Date (-1 if error - test for error by checking for less than 0.1)

    • internalGetExcelDate

      private static double internalGetExcelDate(Calendar date, boolean use1904windowing)

    • getJavaDate

      public static Date getJavaDate(double date, TimeZone tz)
      Given an Excel date with using 1900 date windowing, and converts it to a java.util.Date. Excel Dates and Times are stored without any timezone information. If you know (through other means) that your file uses a different TimeZone to the system default, you can use this version of the getJavaDate() method to handle it.
      Parameters:
      date - The Excel date.
      tz - The TimeZone to evaluate the date in
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaDate

      public static Date getJavaDate(double date)
      Given an Excel date with using 1900 date windowing, and converts it to a java.util.Date. NOTE: If the default TimeZone in Java uses Daylight Saving Time then the conversion back to an Excel date may not give the same value, that is the comparison excelDate == getExcelDate(getJavaDate(excelDate,false)) is not always true. For example if default timezone is Europe/Copenhagen, on 2004-03-28 the minute after 01:59 CET is 03:00 CEST, if the excel date represents a time between 02:00 and 03:00 then it is converted to past 03:00 summer time
      Parameters:
      date - The Excel date.
      Returns:
      Java representation of the date, or null if date is not a valid Excel date
      See Also:

    • getJavaDate

      public static Date getJavaDate(double date, boolean use1904windowing, TimeZone tz)
      Given an Excel date with either 1900 or 1904 date windowing, converts it to a java.util.Date. Excel Dates and Times are stored without any timezone information. If you know (through other means) that your file uses a different TimeZone to the system default, you can use this version of the getJavaDate() method to handle it.
      Parameters:
      date - The Excel date.
      tz - The TimeZone to evaluate the date in
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaDate

      public static Date getJavaDate(double date, boolean use1904windowing, TimeZone tz, boolean roundSeconds)
      Given an Excel date with either 1900 or 1904 date windowing, converts it to a java.util.Date. Excel Dates and Times are stored without any timezone information. If you know (through other means) that your file uses a different TimeZone to the system default, you can use this version of the getJavaDate() method to handle it.
      Parameters:
      date - The Excel date.
      tz - The TimeZone to evaluate the date in
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      roundSeconds - round to closest second
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaDate

      public static Date getJavaDate(double date, boolean use1904windowing)
      Given an Excel date with either 1900 or 1904 date windowing, converts it to a java.util.Date. NOTE: If the default TimeZone in Java uses Daylight Saving Time then the conversion back to an Excel date may not give the same value, that is the comparison excelDate == getExcelDate(getJavaDate(excelDate,false)) is not always true. For example if default timezone is Europe/Copenhagen, on 2004-03-28 the minute after 01:59 CET is 03:00 CEST, if the excel date represents a time between 02:00 and 03:00 then it is converted to past 03:00 summer time
      Parameters:
      date - The Excel date.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      Returns:
      Java representation of the date, or null if date is not a valid Excel date
      See Also:

    • setCalendar

      public static void setCalendar(Calendar calendar, int wholeDays, int millisecondsInDay, boolean use1904windowing, boolean roundSeconds)

    • getJavaCalendar

      public static Calendar getJavaCalendar(double date)
      Get EXCEL date as Java Calendar (with default time zone). This is like getJavaDate(double) but returns a Calendar object.
      Parameters:
      date - The Excel date.
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaCalendar

      public static Calendar getJavaCalendar(double date, boolean use1904windowing)
      Get EXCEL date as Java Calendar (with default time zone). This is like getJavaDate(double, boolean) but returns a Calendar object.
      Parameters:
      date - The Excel date.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaCalendarUTC

      public static Calendar getJavaCalendarUTC(double date, boolean use1904windowing)
      Get EXCEL date as Java Calendar with UTC time zone. This is similar to getJavaDate(double, boolean) but returns a Calendar object that has UTC as time zone, so no daylight saving hassle.
      Parameters:
      date - The Excel date.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      Returns:
      Java representation of the date in UTC, or null if date is not a valid Excel date

    • getJavaCalendar

      public static Calendar getJavaCalendar(double date, boolean use1904windowing, TimeZone timeZone)
      Get EXCEL date as Java Calendar with given time zone.
      Parameters:
      date - The Excel date.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      timeZone - The TimeZone to evaluate the date in
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • getJavaCalendar

      public static Calendar getJavaCalendar(double date, boolean use1904windowing, TimeZone timeZone, boolean roundSeconds)
      Get EXCEL date as Java Calendar with given time zone.
      Parameters:
      date - The Excel date.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      timeZone - The TimeZone to evaluate the date in
      roundSeconds - round to closest second
      Returns:
      Java representation of the date, or null if date is not a valid Excel date

    • isCached

      private static boolean isCached(String formatString, int formatIndex)

    • cache

      private static void cache(String formatString, int formatIndex, boolean cached)

    • isADateFormat

      public static boolean isADateFormat(int formatIndex, String formatString)
      Given a format ID and its format String, will check to see if the format represents a date format or not. Firstly, it will check to see if the format ID corresponds to an internal excel date format (eg most US date formats) If not, it will check to see if the format string only contains date formatting characters (ymd-/), which covers most non US date formats.
      Parameters:
      formatIndex - The index of the format, eg from ExtendedFormatRecord.getFormatIndex
      formatString - The format string, eg from FormatRecord.getFormatString
      See Also:

    • isInternalDateFormat

      public static boolean isInternalDateFormat(int format)
      Given a format ID this will check whether the format represents an internal excel date format or not.
      See Also:

    • isCellDateFormatted

      public static boolean isCellDateFormatted(Cell cell)
      Check if a cell contains a date Since dates are stored internally in Excel as double values we infer it is a date if it is formatted as such.
      See Also:

    • isCellInternalDateFormatted

      public static boolean isCellInternalDateFormatted(Cell cell)
      Check if a cell contains a date, checking only for internal excel date formats. As Excel stores a great many of its dates in "non-internal" date formats, you will not normally want to use this method.
      See Also:

    • isValidExcelDate

      public static boolean isValidExcelDate(double value)
      Given a double, checks if it is a valid Excel date.
      Parameters:
      value - the double value
      Returns:
      true if valid

    • absoluteDay

      protected static int absoluteDay(Calendar cal, boolean use1904windowing)
      Given a Calendar, return the number of days since 1900/12/31.
      Parameters:
      cal - the Calendar
      Returns:
      days number of days since 1900/12/31
      Throws:
      IllegalArgumentException - if date is invalid

    • daysInPriorYears

      private static int daysInPriorYears(int yr, boolean use1904windowing)
      Return the number of days in prior years since 1900
      Parameters:
      yr - a year (1900 < yr < 4000)
      use1904windowing -
      Returns:
      days number of days in years prior to yr.
      Throws:
      IllegalArgumentException - if year is outside of range.

    • dayStart

      private static Calendar dayStart(Calendar cal)

    • convertTime

      public static double convertTime(String timeStr)
      Converts a string of format "HH:MM" or "HH:MM:SS" to its (Excel) numeric equivalent
      Returns:
      a double between 0 and 1 representing the fraction of the day

    • convertTimeInternal

      private static double convertTimeInternal(String timeStr) throws DateUtil.FormatException
      Throws:
      DateUtil.FormatException

    • parseYYYYMMDDDate

      public static Date parseYYYYMMDDDate(String dateStr)
      Converts a string of format "YYYY/MM/DD" to its (Excel) numeric equivalent
      Returns:
      a double representing the (integer) number of days since the start of the Excel epoch

    • parseYYYYMMDDDateInternal

      private static Date parseYYYYMMDDDateInternal(String timeStr) throws DateUtil.FormatException
      Throws:
      DateUtil.FormatException

    • parseInt

      private static int parseInt(String strVal, String fieldName, int rangeMax) throws DateUtil.FormatException
      Throws:
      DateUtil.FormatException

    • parseInt

      private static int parseInt(String strVal, String fieldName, int lowerLimit, int upperLimit) throws DateUtil.FormatException
      Throws:
      DateUtil.FormatException