//以下是年,月,周,天,时,分秒的用法
date("Y-m-d H:i:s", strtotime(" +1 year"));
date("Y-m-d H:i:s", strtotime(" +1 month"));
date("Y-m-d H:i:s", strtotime(" +1 week"));
date("Y-m-d H:i:s", strtotime(" +1 day"));
date("Y-m-d H:i:s", strtotime(" +1 hour"));
date("Y-m-d H:i:s", strtotime(" +1 minute"));
date("Y-m-d H:i:s", strtotime(" +1 second"));
date("Y-m-d H:i:s", strtotime(" +1 year"));
date("Y-m-d H:i:s", strtotime(" +1 month"));
date("Y-m-d H:i:s", strtotime(" +1 week"));
date("Y-m-d H:i:s", strtotime(" +1 day"));
date("Y-m-d H:i:s", strtotime(" +1 hour"));
date("Y-m-d H:i:s", strtotime(" +1 minute"));
date("Y-m-d H:i:s", strtotime(" +1 second"));