Pros

If monthly income remains constant, increasing standard hours reduces hourly wage costs.

Extending standard hours can reduce expensive overtime work.

If the increase in standard hours is not perfectly offset by a reduction in overtime (implying that total hours also go up), fixed labor costs are spread over more hours and capital can be utilized longer.

Increasing standard hours can have positive scale effects if the reduction in costs leads to an increase in output, boosting demand for labor.

The proportion of “non-productive” time devoted to starting up and finishing work likely falls when standard hours rise.