Chapter: jDateTime: dates and times
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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
setFromStringmethod on a jDateTime object. Its argument must be a date-formatted string
Retrieving the current date ¶
The now() method allow to set a jDatetime object to the current date.
$dt = new jDateTime();
$dt->now();
$date = $dt->toString(jDateTime::LANG_DFORMAT);
$date content the current date formatted for the current language in the application.
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
$date2 = new jDateTime(0,0,2);
$dt->sub($date2);
echo $dt->toString(jDateTime::BD_DFORMAT); // displays 2006-04-08
// add 27h15 hours
$date2 = new jDateTime(0,0,0,27,15);
$dt->add($date2);
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
