15.4. Working with Dates and Times
Poprzedni | Rozdział 15. Zend_Locale | Następny

## 15.4. Working with Dates and Times

`Zend_Locale_Format` provides several methods for working with dates and times to help convert and normalize between different formats for different locales. Use `Zend_Date` for manipulating dates, and working with date strings that already conform to one of the many internationally recognized standard formats, or one of the localized date formats supported by `Zend_Date` . Using an existing, pre-defined format offers advantages, including the use of well-tested code, and the assurance of some degree of portability and interoperability (depending on the standard used). The examples below do not follow these recommendations, since using non-standard date formats would needlessly increase the difficulty of understanding these examples.

### 15.4.1. Normalizing Dates and Times

The `getDate()` method parses strings containing dates in localized formats. The results are returned in a structured array, with well-defined keys for each part of the date. In addition, the array will contain a key 'format' showing the format string used to parse the input date string. Since a localized date string may not contain all parts of a date/time, the key-value pairs are optional. For example, if only the year, month, and day is given, then all time values are supressed from the returned array, and vice-versa if only hour, minute, and second were given as input. If no date or time can be found within the given input, an exception will be thrown.

Also, the sister method `getFixedDate()` adds a key 'fixed' with a whole number value indicating if the input date string required "fixing" by rearranging the day, month, or year in the input to fit the format used.

Tabela 15.2. 'fixed' key values

value | meaning |  |
0 | nothing to fix |  |
1 | fixed false month |  |
2 | swapped day and year |  |
3 | swapped month and year |  |
4 | swapped month and day |  |

The following return values are possible, when the BCMath extension is available:

Tabela 15.3. Return values

getDate() format character | Array key | Returned value | Minimum | Maximum
--- | --- | --- | --- | ---
d | day | integer | 1 | 31
M | month | integer | 1 | 12
y | year | integer | no limit | PHP integer's maximum
h | hour | integer | 0 | PHP integer's maximum
m | minute | integer | 0 | PHP integer's maximum
s | second | integer | 0 | PHP integer's maximum

Przykład 15.28. Normalizing a date

    <?php
    require_once 'Zend/Locale.php';

    $date = Zend_Locale_Format::getDate('13.04.2006', 'dd.MM.yyyy');
    $dateObject = Zend_Date('13.04.2006', 'dd.MM.yyyy'); // creates a Zend_Date object for this date

    print_r($date); // outputs:

    Array
    (
        [format] => dd.MM.yyyy
        [day] => 13
        [month] => 4
        [year] => 2006
    )

    // alternatively, some types of problems with input data can be automatically corrected
    $date2 = Zend_Locale_Format::getFixedDate('04.13.2006', 'dd.MM.yyyy');

    print_r($date); // outputs:

    Array
    (
        [format] => dd.MM.yyyy
        [day] => 13
        [month] => 4
        [year] => 2006
        [fixed] => 4
    )
    ?>

Since `getDate()` is "locale-aware", specifying the `$locale` is sufficient for date strings adhering to that locale's format. The method `getFixedDate()` uses simple tests to determine if the day or month is not valid, and then applies heuristics to try and correct any detected problems.

Przykład 15.29. Normalizing a date by locale

    <?php
    require_once 'Zend/Locale.php';

    $locale = new Zend_Locale('de_AT');
    $date = Zend_Locale_Format::getDate('13.04.2006', null, $locale);

    print_r ($date);
    ?>

A complete date and time is returned when the input contains both a date and time in the expected format.

Przykład 15.30. Normalizing a date with time

    <?php
    require_once 'Zend/Locale.php';

    $locale = new Zend_Locale('de_AT');
    $date = Zend_Locale_Format::getDate('13.04.2005 22:14:55', false, $locale);

    print_r ($date);
    ?>

If a specific format is desired, specify the `$format` argument, without giving a `$locale`. Only single-letter codes (H, m, s, y, M, d), and MMMM and EEEE are supported in the `$format`.

Przykład 15.31. Normalizing a userdefined date

    <?php
    require_once 'Zend/Locale.php';

    $date = Zend_Locale_Format::getDate('13200504T551422', 'ddyyyyMM ssmmHH');

    print_r ($date);
    ?>

The format can include the following signs :

Tabela 15.4. Format definition

Format Letter | Description
--- | ---
d or dd | 1 or 2 digit day
M or MM | 1 or 2 digit month
y or yy | 1 or 2 digit year
yyyy | 4 digit year
h | 1 or 2 digit hour
m | 1 or 2 digit minute
s | 1 or 2 digit second

Examples for proper formats are

Tabela 15.5. Example formats

Formats | Input | Output
--- | --- | ---
dd.MM.yy | 1.4.6 | ['day'] => 1, ['month'] => 4, ['year'] => 6
dd.MM.yy | 01.04.2006 | ['day'] => 1, ['month'] => 4, ['year'] => 2006
yyyyMMdd | 1.4.6 | ['day'] => 6, ['month'] => 4, ['year'] => 1

| Database date format
To parse a database date value (f.e. MySql or MsSql), use Zend_Date's ISO_8601 format instead of getDate().

The method `getFixedDate()` uses simple tests to determine if the day or month is not valid, and then applies heuristics to try and correct any detected problems. `getDate()` automatically detects and corrects some kinds of problems with input, such as misplacing the year:

Przykład 15.32. Automatic correction of input dates

    <?php
    require_once 'Zend/Locale.php';

    $date = Zend_Locale_Format::getFixedDate('41.10.20', 'ddMMyy');

    // instead of 41 for the day, the 41 will be returned as year value
    print_r ($date);
    ?>

### 15.4.2. Testing Dates

Use `isDate()` to check if a given string contains a valid date. The `isDate()` method uses `getDate()`, not `getFixedDate()` to avoid returning true when the input fails to conform to the date format.

Przykład 15.33. Date testing

    <?php
    require_once 'Zend/Locale.php';

    $locale = new Zend_Locale('de_AT');
    if (Zend_Locale_Format::isDate('13.Apr.2006', $locale) {
        print "date";
    } else {
        print "not a date";
    }
    ?>

### 15.4.3. Normalizing a Time

Normally, a time will be returned with a date, if the input contains both. If the proper format is not known, but the locale relevant to the user input is known, then `getTime()` should be used, because it uses the default time format for the selected locale.

Przykład 15.34. Normalize an unknown time

    <?php
    require_once 'Zend/Locale.php';

    $locale = new Zend_Locale('de_AT');
    if (Zend_Locale_Format::getTime('13:44:42', $locale) {
        print "time";
    } else {
        print "not a time";
    }
    ?>

### 15.4.4. Testing Times

Use `isTime()` to check if a given string contains a proper time.

Przykład 15.35. Testing a time

    <?php
    require_once 'Zend/Locale.php';

    $locale = new Zend_Locale('de_AT');
    if (Zend_Locale_Format::isTime('13:44:42', $locale) {
        print "time";
    } else {
        print "not a time";
    }
    ?>

Poprzedni | Początek rozdziału | Następny
15.3. Normalization and Localization | Spis treści | 15.5. Supported Languages for Locales