Fix RFM date range consistency

src/dateRanges.ts

@@ -0,0 +1,58 @@
+import type { DateRange } from './types';
+
+export const startOfLocalDay = (date: Date): Date => {
+  const nextDate = new Date(date);
+  nextDate.setHours(0, 0, 0, 0);
+  return nextDate;
+};
+
+export const endOfLocalDay = (date: Date): Date => {
+  const nextDate = new Date(date);
+  nextDate.setHours(23, 59, 59, 999);
+  return nextDate;
+};
+
+export const rangeForDay = (date: Date): DateRange => ({
+  start: startOfLocalDay(date),
+  end: endOfLocalDay(date),
+});
+
+export const rangeForLastDays = (days: number, today = new Date()): DateRange => {
+  const end = endOfLocalDay(today);
+  const start = startOfLocalDay(today);
+  start.setDate(start.getDate() - Math.max(days - 1, 0));
+  return { start, end };
+};
+
+export const rangeForPreviousDay = (today = new Date()): DateRange => {
+  const date = startOfLocalDay(today);
+  date.setDate(date.getDate() - 1);
+  return rangeForDay(date);
+};
+
+export const parseLocalDateInput = (value: string): Date | null => {
+  if (!value) return null;
+
+  const match = value.match(/^(\d{4})-(\d{2})-(\d{2})$/);
+  if (!match) return null;
+
+  const [, yearValue, monthValue, dayValue] = match;
+  const date = new Date(Number(yearValue), Number(monthValue) - 1, Number(dayValue));
+
+  if (
+    date.getFullYear() !== Number(yearValue) ||
+    date.getMonth() !== Number(monthValue) - 1 ||
+    date.getDate() !== Number(dayValue)
+  ) {
+    return null;
+  }
+
+  return date;
+};
+
+export const formatDateParam = (date: Date): string => {
+  const year = date.getFullYear();
+  const month = String(date.getMonth() + 1).padStart(2, '0');
+  const day = String(date.getDate()).padStart(2, '0');
+  return `${year}-${month}-${day}`;
+};