Question

on what day approximately the sun will be overhead (noon) at a place located on the latitude 8.57 deg

Answer 1

Most likely the least demanding path is to consider where the area is in respect to the separation from the equator or line of tropic. In the event that the area is somewhere between the equator and the line of tropic (~11,75 degrees), at that point somewhere between the equinox and the solstice the Sun will be overhead for that scope (clearly December solstice for the south of the equator and June solstice north of the equator).  

In case you're allowed to take a look at a almanac, you should simply observe when the sun's declination is equivalent to the scope you're keen on. The main confusion is that map latitude doesn't precisely break even with scope by the stars, yet the distinction barely ever surpasses 0.01 degree.