Question

all

Decrease month by one in strtotime in this loop.

$twitter_val7 .='{
                            date: new Date('.date("Y",strtotime($date)).', '.date("m",strtotime($date)).', '.date("d",strtotime($date)).'),
                            value: '.$result_twitter->counts.'
                            },';

Answer 1

To decrease by 1 month using strtotime() you literally tell it to decrease by one month:

strtotime($date . ' - 1 month');

Assuming, of course, that $date is a format strtotime() understands.