MemberPress: Dynamic Trail Periods

function mepr_days_until( $date ){

    return ( isset( $date ) ) ? floor( ( strtotime( $date ) - time() )/60/60/24 ) : false;

}

function mepr_update_mepr_trial_period() {

  $prd = new MeprProduct( 4480 ); //CHANGE 123 to the ID of your Membership level

  $last_check = get_option( 'mepr_trial_period_last_checked-'.$prd->ID, 0 );

  if( time() - $last_check <= 3600 ) { return; } //Only do this once per hour

  $curr_month_of_year = gmdate( 'n' );

  if( $curr_month_of_year >= 4 ) {

    //Get next year's march 31st

    $days = mepr_days_until( gmdate( ( gmdate( 'Y' )+1 ).'-03-31' ) );

  }

  else {

    //Get this year's march 31st

    $days = mepr_days_until( gmdate( gmdate( 'Y' ).'-03-31' ) );

  }

  $prd->trial = true;

  $prd->trial_days = $days;

  $prd->store();

  update_option( 'mepr_trial_period_last_checked-'.$prd->ID, time() );

}

add_action( 'init', 'mepr_update_mepr_trial_period' );