Languages Around The World

Format Date and Time Examples

Overview

The ICU DateFormat interface enables you to format a date in milliseconds into a string representation of the date. Also, the interface enables you to parse the string back to the internal date representation in milliseconds.

C++

DateFormat* df = DateFormat::createDateInstance();
UnicodeString myString;
UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; 
for (int32_t i = 0; i < 3; ++i) {
  myString.remove();
  cout << df->format( myDateArr[i], myString ) << endl;
}

C

 /* 1st example: format the dates in millis 100000000 and
2000000000 */
UErrorCode status=U_ZERO_ERROR;
int32_t i, myStrlen=0;
UChar* myString;
UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
UDateFormat* df = udat_open(UCAL_DEFAULT, UCAL_DEFAULT, NULL, "GMT", &status);
for (i = 0; i < 3; ++i) {
  myStrlen = udat_format(df, myDateArr[i], NULL, myStrlen, NULL, &status);
  if(status==U_BUFFER_OVERFLOW_ERROR){
    status=U_ZERO_ERROR;
    myString=(UChar*)malloc(sizeof(UChar) * (myStrlen+1) );
    udat_format(df, myDateArr[i], myString, myStrlen+1, NULL, &status);
    printf("%s\n", austrdup(myString) ); 
    /* austrdup( a function used to convert UChar* to char*) */
    free(myString);
  }
}

To parse a date for a different locale, specify it in the locale call. This call creates a formatting object.

C++

DateFormat* df = DateFormat::createDateInstance
  ( DateFormat::SHORT, Locale::getFrance());

C

/* 2nd example: parse a date with short French date/time
formatter */
UDateFormat* df = udat_open(UDAT_SHORT, UDAT_SHORT, "fr_FR", "GMT", &status);
UErrorCode status = U_ZERO_ERROR;
int32_t parsepos=0;     
UDate myDate = udat_parse(df, myString, u_strlen(myString), &parsepos,
&status);

To get specific fields of a date, you can use the FieldPosition function for C++ or UFieldPosition function for C.

C++

UErrorCode status = U_ZERO_ERROR;
FieldPosition pos(DateFormat::YEAR_FIELD)
UDate myDate = Calendar::getNow();
UnicodeString str;
DateFormat* df = DateFormat::createDateInstance
  ( DateFormat::LONG, Locale::getFrance());

df->format(myDate, str, pos, status);
cout << pos.getBeginIndex() << "," << pos. getEndIndex() << endl;

C

UErrorCode status = U_ZERO_ERROR;
  UFieldPosition pos;
  UChar *myString;
  int32_t myStrlen = 0;
  char buffer[1024];


  pos.field = 1;  /* Same as the DateFormat::EField enum */
  UDateFormat* dfmt = udat_open(UCAL_DEFAULT, UCAL_DEFAULT, NULL, "PST",
&status);
  myStrlen = udat_format(dfmt, myDate, NULL, myStrlen, &pos, &status);
  if (status==U_BUFFER_OVERFLOW_ERROR){
      status=U_ZERO_ERROR;
      myString=(UChar*)malloc(sizeof(UChar) * (myStrlen+1) );
      udat_format(dfmt, myDate, myString, myStrlen+1, &pos, &status);
  }
  printf("date format: %s\n", u_austrcpy(buffer, myString));
  buffer[pos.endIndex] = 0;   // NULL terminate the string.
  printf("UFieldPosition position equals %s\n", &buffer[pos.beginIndex]);



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User Guide for ICU v3.4 Generated 2005-07-27.