function _wc_save_product_price( $product_id, $regular_price, $sale_price = '', $date_from = '', $date_to = '' ) {
  wc_doing_it_wrong( '_wc_save_product_price()', 'This function is not for developer use and is deprecated.', '3.0' );

  $product_id    = absint( $product_id );
  $regular_price = wc_format_decimal( $regular_price );
  $sale_price    = '' === $sale_price ? '' : wc_format_decimal( $sale_price );
  $date_from     = wc_clean( $date_from );
  $date_to       = wc_clean( $date_to );

  update_post_meta( $product_id, '_regular_price', $regular_price );
  update_post_meta( $product_id, '_sale_price', $sale_price );

  // Save Dates
  update_post_meta( $product_id, '_sale_price_dates_from', $date_from ? strtotime( $date_from ) : '' );
  update_post_meta( $product_id, '_sale_price_dates_to', $date_to ? strtotime( $date_to ) : '' );

  if ( $date_to && ! $date_from ) {
    $date_from = strtotime( 'NOW', current_time( 'timestamp' ) );
    update_post_meta( $product_id, '_sale_price_dates_from', $date_from );
  }

  // Update price if on sale
  if ( '' !== $sale_price && '' === $date_to && '' === $date_from ) {
    update_post_meta( $product_id, '_price', $sale_price );
  } else {
    update_post_meta( $product_id, '_price', $regular_price );
  }

  if ( '' !== $sale_price && $date_from && strtotime( $date_from ) < strtotime( 'NOW', current_time( 'timestamp' ) ) ) {
    update_post_meta( $product_id, '_price', $sale_price );
  }

  if ( $date_to && strtotime( $date_to ) < strtotime( 'NOW', current_time( 'timestamp' ) ) ) {
    update_post_meta( $product_id, '_price', $regular_price );
    update_post_meta( $product_id, '_sale_price_dates_from', '' );
    update_post_meta( $product_id, '_sale_price_dates_to', '' );
  }
}