Hi Rich…
Since you want both comparisons to be true, you can include an “AND relation” within the query:
array(
'relation' => 'AND',
array(
'key' => 'offer_start_date',
'value' => $today,
'compare' => '<='
),
array(
'key' => 'offer_end_date',
'value' => $today,
'compare' => '>='
)
)
Also, here are more docs on date queries that may be useful.