let obj = {
0: {title: "событие 5", start: "02:30", end: "06:00", week: "Thursday"},
1: {title: "событие 1", start: "06:00", end: "15:30", week: "Thursday"},
2: {title: "событие 2", start: "15:30", end: "21:00", week: "Thursday"},
3: {title: "событие 3", start: "21:00", end: "00:00", week: "Thursday"},
4: {title: "событие 4", start: "00:00", end: "02:30", week: "Thursday"}
}
Object.values(obj).sort((a, b) => a.start.localeCompare(b.start))