the date() function needs a string as the 1st argument, which is the format. the time(), should be the 2nd argument, like: date('Y-m-d H:i:s', time()). this will return a string, that you can use with a DATETIME column. other than that, if you want to store a unix timestamp, just use an INT column. so you can store the result of time() directly, without calling date. (or, as i said before, format the timestamp using date() with a valid format string and use a DATE, DATETIME, or TIMESTAMP column). see: http://www.php.net/manual/en/function.date.php and http://dev.mysql.com/doc/refman/5.1/en/datetime.html
EDIT: the 0's you are seeing, are there because mysql did not recognice the format you used for the column (so if you are using a DATE column but you're passing it the wrong format, it is not recogniced, so a 0 is saved)
datecolumn? You are trying to insert an integer. Also, I would highly recommend using a DATETIME or TIMESTAMP column instead of storing integers. You can use the MySQL function NOW() to insert the current time into a DATETIME/TIMESTAMP column.