I am really pulling my hair now and going crazy:

  const {year, month} = req.headers;
  const date_range_from = new Date(year, month, 1);  
  const date_range_to = new Date(year, month + 1, 1); // wrong year; why?   
  
  console.log("year, month: ", year, month)
  console.log("date_range_from, date_range_to: ", date_range_from, date_range_to)

The console log gives:

year, month:  2021 6
date_range_from, date_range_to:  2021-06-30T15:00:00.000Z 2026-01-31T15:00:00.000Z

WHY 2026 ???? What is going on???