Best solution would be:
$monday = date( 'Y-m-d', strtotime( 'monday this week' ) );
$friday = date( 'Y-m-d', strtotime( 'friday this week' ) );
Best solution would be:
$monday = date( 'Y-m-d', strtotime( 'monday this week' ) );
$friday = date( 'Y-m-d', strtotime( 'friday this week' ) );