Вы можете сделать что-то вроде этого:
<script>
function ShowOnTime(element){
var daysWorking = [{dayWorking: 1, startTimeWorking: '8', endTimeWorking: '19'}, {dayWorking: 2, startTimeWorking: '8', endTimeWorking: '19'}, {dayWorking: 3, startTimeWorking: '8', endTimeWorking: '19'}, {dayWorking: 4, startTimeWorking: '8', endTimeWorking: '19'}, {dayWorking: 5, startTimeWorking: '8', endTimeWorking: '19'}, {dayWorking: 6, startTimeWorking: '830', endTimeWorking: '16'}];
var a = new Date();
var nowDay = a.getDay(); //0-6 denotes Sunday, monday, tuesday etc etc.
var nowHours = a.getHours();
var nowMinutes = a.getMinutes();
if(daysWorking.find(o => o.dayWorking === nowDay)){
if (daysWorking.find(o => o.startTimeWorking <= (nowHours+''+nowMinutes)) && daysWorking.find(o => o.endTimeWorking >= (nowHours+''+nowMinutes))) {
$(element).show();
} else {
$(element).hide();
}
} else {
$(element).hide();
}
}
$(document).ready(function(){
ShowOnTime("#TestDiv");
});
</script>
Надеюсь, это даст вам некоторое представление.