How do I get next month date from today’s date and insert it in my database?

I have two columns in my db: start_date and end_date, which are both DATE types. My code is updating the dates as follows:

$today_date = date("Y-m-d");
$end_date = date("Y-m-d"); // date +1 month ??

$sql1 = "UPDATE `users` SET `start_date` = '".$today_date."', `end_date` = '".$end_date."'  WHERE `users`.`id` ='".$id."' LIMIT 1 ;";

What is the best way to make $end_date equal to $start_date + one month? For example, 2000-10-01 would become 2000-11-01.

Answer

You can use PHP’s strtotime() function:

// One month from today
$date = date('Y-m-d', strtotime('+1 month'));

// One month from a specific date
$date = date('Y-m-d', strtotime('+1 month', strtotime('2015-01-01')));

Just note that +1 month is not always calculated intuitively. It appears to always add the number of days that exist in the current month.

Current Date  | +1 month
-----------------------------------------------------
2015-01-01    | 2015-02-01   (+31 days)
2015-01-15    | 2015-02-15   (+31 days)
2015-01-30    | 2015-03-02   (+31 days, skips Feb)
2015-01-31    | 2015-03-03   (+31 days, skips Feb)
2015-02-15    | 2015-03-15   (+28 days)
2015-03-31    | 2015-05-01   (+31 days, skips April)
2015-12-31    | 2016-01-31   (+31 days)

Some other date/time intervals that you can use:

$date = date('Y-m-d'); // Initial date string to use in calculation

$date = date('Y-m-d', strtotime('+1 day', strtotime($date)));
$date = date('Y-m-d', strtotime('+1 week', strtotime($date)));
$date = date('Y-m-d', strtotime('+2 week', strtotime($date)));
$date = date('Y-m-d', strtotime('+1 month', strtotime($date)));
$date = date('Y-m-d', strtotime('+30 days', strtotime($date)));