SQL - DATE

Always using Interval x day to calculate the days

INTERVAL 1 DAY

Subtract 1 day from NOW()

...WHERE DATE_FIELD >= DATE_SUB(NOW(), INTERVAL 1 DAY)

Add 1 day from NOW()

...WHERE DATE_FIELD >= DATE_ADD(NOW(), INTERVAL 1 DAY)

Select str_to_date("Augest 31 2017", "%M %d %Y") + Interval 1 day from dual

<<From dual means from a dummy table