feat: Timeline UI (#2830)

web/src/utils/dateUtil.ts

@@ -0,0 +1,16 @@
+export const longToDate = (long: number): Date => new Date(long * 1000);
+export const epochToLong = (date: number): number => date / 1000;
+export const dateToLong = (date: Date): number => epochToLong(date.getTime());
+
+const getDateTimeYesterday = (dateTime: Date): Date => {
+  const twentyFourHoursInMilliseconds = 24 * 60 * 60 * 1000;
+  return new Date(dateTime.getTime() - twentyFourHoursInMilliseconds);
+}
+
+const getNowYesterday = (): Date => {
+  return getDateTimeYesterday(new Date());
+}
+
+export const getNowYesterdayInLong = (): number => {
+  return dateToLong(getNowYesterday());
+};