Sejmon,
var time = "6:00 7:30 8:30 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 21:30".split(" "),
out = [], forTime = (new Date()).getHours()+":"+(new Date()).getMinutes();
for (var i=0; i<time.length; i++) {
if (+time[i].replace(":","")>+forTime.replace(":",""))
{for (var k=i-2; k<i+2; k++) {
time[k] && out.push(time[k])
};break}
}
alert(forTime+"=>"+out);