Class DateUtil

java.lang.Object
org.apache.poi.ss.usermodel.DateUtil
Direct Known Subclasses:
HSSFDateUtil

public class DateUtil extends Object
Contains methods for dealing with Excel dates.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final long
     
    static final int
     
    static final int
     
    static final int
     
    static final int
     
  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
     
  • Method Summary

    Modifier and Type
    Method
    Description
    protected static int
    absoluteDay(Calendar cal, boolean use1904windowing)
    Given a Calendar, return the number of days since 1900/12/31.
    static double
    Converts a string of format "HH:MM" or "HH:MM:SS" to its (Excel) numeric equivalent
    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.
    static double
    Given a Date, converts it into a double representing its internal Excel representation, which is the number of days since 1/1/1900.
    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.
    static Calendar
    getJavaCalendar(double date)
    Get EXCEL date as Java Calendar (with default time zone).
    static Calendar
    getJavaCalendar(double date, boolean use1904windowing)
    Get EXCEL date as Java Calendar (with default time zone).
    static Calendar
    getJavaCalendar(double date, boolean use1904windowing, TimeZone timeZone)
    Get EXCEL date as Java Calendar with given time zone.
    static Calendar
    getJavaCalendar(double date, boolean use1904windowing, TimeZone timeZone, boolean roundSeconds)
    Get EXCEL date as Java Calendar with given time zone.
    static Calendar
    getJavaCalendarUTC(double date, boolean use1904windowing)
    Get EXCEL date as Java Calendar with UTC time zone.
    static Date
    getJavaDate(double date)
    Given an Excel date with using 1900 date windowing, and converts it to a java.util.Date.
    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.
    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.
    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.
    static Date
    getJavaDate(double date, TimeZone tz)
    Given an Excel date with using 1900 date windowing, and converts it to a java.util.Date.
    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.
    static boolean
    Given a format ID and its format String, will check to see if the format represents a date format or not.
    static boolean
    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.
    static boolean
    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.
    static boolean
    Check if a cell contains a date, checking only for internal excel date formats.
    static boolean
    Given a format ID this will check whether the format represents an internal excel date format or not.
    static boolean
    isValidExcelDate(double value)
    Given a double, checks if it is a valid Excel date.
    static Date
    Converts a string of format "YYYY/MM/DD" to its (Excel) numeric equivalent
    static void
    setCalendar(Calendar calendar, int wholeDays, int millisecondsInDay, boolean use1904windowing, boolean roundSeconds)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • 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)
    • 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.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      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, 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.
      use1904windowing - true if date uses 1904 windowing, or false if using 1900 date windowing.
      tz - 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
    • 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
    • isADateFormat

      public static boolean isADateFormat(ExcelNumberFormat numFmt)
      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:
      numFmt - The number format index and string expression, or null if not specified
      Returns:
      true if it is a valid date format, false if not or null
      See Also:
    • 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
      Returns:
      true if it is a valid date format, false if not or null
      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.
      Parameters:
      cell -
      Returns:
      true if it looks like a date
      See Also:
    • isCellDateFormatted

      public static boolean isCellDateFormatted(Cell cell, ConditionalFormattingEvaluator cfEvaluator)
      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. Format is determined from applicable conditional formatting, if any, or cell style.
      Parameters:
      cell -
      cfEvaluator - if available, or null
      Returns:
      true if it looks like a date
      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
    • 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
    • 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