How to use preg_replace to add one hour to a time value?

I have a page that shows times on it like this: 10:00am. I need to take those times, and add one 开发者_如何学Pythonhour to them. I have come up with a regular expression to deal with finding the times themselves, I just don't know what to do next. This is the regex I have: ^(1[012]|[1-9]):([0-5][0-9])(?i)(am|pm)^.

Any help would be greatly appreciated. -Austin

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You can also use this one-liner: echo date("h:ia", strtotime("10:43am +1 hour"));, replace 10:43 with an interpolated variable and make sure it's parsable by strtotime() (your example format is).

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You can do something like this, don't need any regexes:

$time = '10:00am';
list($hour, $min) = explode(':', $time);
echo date('h:ia', mktime((int)$hour + 1, (int)$min));

Casting to int gets rid of the trailing am so that the minutes part can be used in mktime.

If you need to use the regex (for example, you are searching for times inside a larger string), you can use this:

preg_match('~^(1[012]|[1-9]):([0-5][0-9])(?i)(am|pm)^~', $str, $matches);
echo date('h:ia', mktime($match[1] + 1, $match[2]));

And, if you need to replace those times inside the original string, you can use preg_replace_callback:

$time = preg_replace_callback('~(1[012]|[1-9]):([0-5][0-9])(?i)(am|pm)~', 
            function($matches) {
                return date('h:ia', mktime($matches[1] + 1, $matches[2]));
            },
        $time);

Version for PHP 5.2 and older:

$time = preg_replace_callback('~(1[012]|[1-9]):([0-5][0-9])(?i)(am|pm)~', 
            create_function(
                '$matches',
                'return date(\'h:ia\', mktime($matches[1] + 1, $matches[2]));'
            },
        $time);

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Parse the time to "part" variables, perform your modifications, and put the parts back into a new string.

For example:

$time = '10:00am';
$time = substr($time, 0, 5);
$ampm = substr($time, 6);
list($hours, $minutes) = explode(':', $time);

// do your thing

$newtime = sprintf('%02d:%02d%s', $hours, $minutes, $ampm);