Tivok,
$(function() {
var d = new Date();
var day = d.getDay();
var time = d.getHours();
var minutes = d.getMinutes();
time *= 100;
time += minutes;
if (day >= 1 && day <= 5 && time >= 910 && time < 1200 ){
$("#block-block-14").css("display", "block");
}
else {
$("#block-block-1").css("display", "block");
}});