MCP Time Server Node

const { parseISO, differenceInCalendarDays, startOfDay } = require('date-fns'); const { formatInTimeZone } = require('date-fns-tz'); // Correct implementation of timezone-aware relative formatting function formatRelativeInTimezone(date, baseDate, timezone) { // Format the time in the target timezone const timeStr = formatInTimeZone(date, timezone, 'h:mm a'); const dayOfWeek = formatInTimeZone(date, timezone, 'EEEE'); // Get start of day for both dates in UTC for accurate day counting const dateStartUTC = startOfDay(date); const baseStartUTC = startOfDay(baseDate); // Calculate calendar days difference const daysDiff = differenceInCalendarDays(dateStartUTC, baseStartUTC); // Build the relative string if (daysDiff === 0) { return `today at ${timeStr}`; } else if (daysDiff === -1) { return `yesterday at ${timeStr}`; } else if (daysDiff === 1) { return `tomorrow at ${timeStr}`; } else if (daysDiff >= -6 && daysDiff < -1) { return `last ${dayOfWeek} at ${timeStr}`; } else if (daysDiff > 1 && daysDiff < 7) { return `${dayOfWeek} at ${timeStr}`; } else { // For dates beyond a week, return the date return formatInTimeZone(date, timezone, 'MM/dd/yyyy'); } } // Test with the problematic case const testDate = parseISO('2024-01-01T09:30:00.000Z'); const baseDate = parseISO('2024-01-03T14:00:00.000Z'); console.log('Test Date:', testDate.toISOString()); console.log('Base Date:', baseDate.toISOString()); console.log(''); // Test in different timezones const timezones = ['America/New_York', 'Asia/Tokyo', 'UTC']; timezones.forEach((tz) => { console.log(`\nTimezone: ${tz}`); const result = formatRelativeInTimezone(testDate, baseDate, tz); console.log('Result:', result); // Show what time it actually is in that timezone const actualTime = formatInTimeZone(testDate, tz, "EEEE, MMMM do, yyyy 'at' h:mm a zzz"); console.log('Actual time:', actualTime); }); // Test edge cases console.log('\n=== Edge Cases ==='); const edgeCases = [ { desc: 'Same day', date: '2024-01-03T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: 'Yesterday', date: '2024-01-02T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: 'Tomorrow', date: '2024-01-04T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: '6 days ago', date: '2023-12-28T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: '7 days ago', date: '2023-12-27T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: '6 days ahead', date: '2024-01-09T09:00:00Z', base: '2024-01-03T14:00:00Z' }, { desc: '7 days ahead', date: '2024-01-10T09:00:00Z', base: '2024-01-03T14:00:00Z' }, ]; edgeCases.forEach(({ desc, date, base }) => { console.log(`\n${desc}:`); const d = parseISO(date); const b = parseISO(base); timezones.forEach((tz) => { const result = formatRelativeInTimezone(d, b, tz); console.log(` ${tz}: ${result}`); }); }); // Test with current date as base console.log('\n=== Using current date as base ==='); const now = new Date(); const testDates = [ new Date(now.getTime() - 2 * 24 * 60 * 60 * 1000), // 2 days ago new Date(now.getTime() - 24 * 60 * 60 * 1000), // yesterday now, // today new Date(now.getTime() + 24 * 60 * 60 * 1000), // tomorrow new Date(now.getTime() + 3 * 24 * 60 * 60 * 1000), // 3 days ahead ]; testDates.forEach((date) => { console.log(`\nDate: ${date.toISOString()}`); timezones.forEach((tz) => { const result = formatRelativeInTimezone(date, now, tz); console.log(` ${tz}: ${result}`); }); });