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jDateTime is a class encapsulating a date. It defines an API to convert date to different formats and do some time calculation.

There is different ways to create a jDateTime object:

  • either pass a date value to jDateTime constructor : year, month, day, hour, minute, second arguments are all integer values and optional.
  • either use setFromString method on a jDateTime object. Its argument must be a date-formatted string

Convert a string to date-time

setFromString, as said before, takes a string as first argument and an optional format type as last argument. The latter is a numeric value. jDateTime defines in its namespace, constants enumerating those formats.

lists of date and time formats accepted by jDateTime:

constantes de classe format
jDateTime::LANG_DFORMAT date format of current application lang (with en, this is mm/jj/aaaa)
jDateTime::LANG_DTFORMAT date and time format of current application lang
jDateTime::LANG_TFORMAT time format of current application lang
jDateTime::BD_DFORMAT date format of classic database style: "AAAA-MM-JJ"
jDateTime::BD_DTFORMAT date and time format of classic database style: "AAAA-MM-JJ HH:mm:SS"
jDateTime::BD_TFORMAT time format of classic database style: "HH:mm:SS"
jDateTime::ISO8601_FORMAT ISO8601 format
jDateTime::TIMESTAMP_FORMAT integer, number of seconds since 1/1/1970

Note: LANG_* formats are converted by jDateTime based on locales format file located in jelix module and current lang selected by your application.

Example :


  $dt = new jDateTime();

  $dt->setFromString("2006-04-10",jDateTime::BD_DFORMAT);

  echo "your date is ", $dt->year, ",", $dt->month, ",", $dt->day, ",", $dt->hour, ",", $dt->minute, ",", $dt->second;

You'll have noticed all member properties representing elements of a date.

defaultFormat property allows to not specify a format for each jDateTime method call.


  $dt = new jDateTime();
  $dt->defaultFormat = jDateTime::BD_DFORMAT;

  $dt->setFromString("2006-04-10");

Convert date-time to string

toString method convert date to string. It accepts an optional argument specifying a format (see above for formats).


  $dt->toString(jDateTime::LANG_DFORMAT);

date-time calcuation

sub and add methods does substract or add duration to a date.


  $dt = new jDateTime();
  $dt->setFromString("2006-04-10",jDateTime::BD_DFORMAT);

  // substract 2 days
  $dt->sub(0,0,2);
  echo $dt->toString(jDateTime::BD_DFORMAT); // displays 2006-04-08

  // add 27h15 hours
  $dt->add(0,0,0,27,15);
  echo $dt->toString(jDateTime::BD_DTFORMAT); // displays 2006-04-09 03:15:00

durationTo method gives the duration between two dates. it returns a jDateTime object:


  $dt = new jDateTime();
  $dt->setFromString("2006-04-10",jDateTime::BD_DFORMAT);

  $dt2 = new jDateTime();
  $dt2->setFromString("2006-04-12",jDateTime::BD_DFORMAT);

  // duration between $dt and $dt2
  $dt3 = $dt->durationTo($dt2);
  echo $dt3->toString(jDateTime::BD_DTFORMAT); // displays 0000-00-02 00:00:00

Note: be aware to use dates superior to 01/01/1970.

date-time comparison

compareTo method compares two dates


  $dt = new jDateTime();
  $dt->setFromString("2006-04-10",jDateTime::BD_DFORMAT);

  $dt2 = new jDateTime();
  $dt2->setFromString("2006-04-12",jDateTime::BD_DFORMAT);

  $result = $dt->compareTo($dt2);

compareTo returns:

  • -1 if $dt < $dt2
  • 0 if dates are equal
  • 1 if $dt > $dt2