How do I generate a random time interval and add it to a mysql datetime using php?

Question

I have many rows in mysql table with datetime\'s in the format of:

2008-12-08 04:16:51 etc

I\'d like to generate a random time interval of

Answer 1

easier way.

$new_date = date('Y-m-d h:i:s', strtotime('2008-12-08 04:16:51 +'.rand(30, 60 * 60 * 24 * 3).' seconds'));

Answer 2

Would you be able to use a random unix timestamp and convert into the MySQL timestamp format? I would assume you could so something like:

$randomTime = time() + rand( 30, 86400 * 3 );   // since there are 86400 seconds in a day,
                                                        // this should generate a random time
                                                        // 3-30 days from now
$randomTimeString = date( "Y-m-d H:i:s", $randomTime ); // format the date (php.net/date)
$st = $mysqli->query( "...", $randomTimeString );       // insert it into the database
...

This probably isn't the most efficient solution, but it should work.

Answer 3

Using MySQL's rand() function:

update [table] set [field] = now() + interval floor(rand()*(60*60*24*3)) second;

wil get you the current datetime + between 0 seconds and three days.