Enhances date handling and formatting

Improves date validation and adds flexible date/time formatting capabilities.

The date validation is updated to return a boolean and is incorporated directly into calling functions to throw errors, improving code readability and maintainability. DateService is extended with functions for formatting time in 12-hour format, getting day names, and formatting date ranges with customizable options.

src/utils/DateCalculator.ts

@@ -25,13 +25,10 @@ export class DateCalculator {
   /**
    * Validate that a date is valid
    * @param date - Date to validate
-   * @param methodName - Name of calling method for error messages
-   * @throws Error if date is invalid
+   * @returns True if date is valid, false otherwise
    */
-  private static validateDate(date: Date, methodName: string): void {
-    if (!date || !(date instanceof Date) || !DateCalculator.dateService.isValid(date)) {
-      throw new Error(`${methodName}: Invalid date provided - ${date}`);
-    }
+  private static validateDate(date: Date): boolean {
+    return date && date instanceof Date && DateCalculator.dateService.isValid(date);
   }
 
   /**
@@ -40,7 +37,9 @@ export class DateCalculator {
    * @returns Array of dates for the configured work days
    */
   static getWorkWeekDates(weekStart: Date): Date[] {
-    DateCalculator.validateDate(weekStart, 'getWorkWeekDates');
+    if (!DateCalculator.validateDate(weekStart)) {
+      throw new Error('getWorkWeekDates: Invalid date provided');
+    }
     
     const dates: Date[] = [];
     const workWeekSettings = DateCalculator.config.getWorkWeekSettings();
@@ -66,7 +65,9 @@ export class DateCalculator {
    * @returns The Monday of the ISO week
    */
   static getISOWeekStart(date: Date): Date {
-    DateCalculator.validateDate(date, 'getISOWeekStart');
+    if (!DateCalculator.validateDate(date)) {
+      throw new Error('getISOWeekStart: Invalid date provided');
+    }
     
     const weekBounds = DateCalculator.dateService.getWeekBounds(date);
     return DateCalculator.dateService.startOfDay(weekBounds.start);
@@ -78,7 +79,9 @@ export class DateCalculator {
    * @returns The end date of the ISO week (Sunday)
    */
   static getWeekEnd(date: Date): Date {
-    DateCalculator.validateDate(date, 'getWeekEnd');
+    if (!DateCalculator.validateDate(date)) {
+      throw new Error('getWeekEnd: Invalid date provided');
+    }
     
     const weekBounds = DateCalculator.dateService.getWeekBounds(date);
     return DateCalculator.dateService.endOfDay(weekBounds.end);
@@ -137,9 +140,12 @@ export class DateCalculator {
   /**
    * Format a date to ISO date string (YYYY-MM-DD) using DateService
    * @param date - Date to format
-   * @returns ISO date string
+   * @returns ISO date string or empty string if invalid
    */
   static formatISODate(date: Date): string {
+    if (!DateCalculator.validateDate(date)) {
+      return '';
+    }
     return DateCalculator.dateService.formatDate(date);
   }
 

src/utils/DateService.ts

@@ -3,24 +3,25 @@
  * Handles all date operations, timezone conversions, and formatting
  */
 
-import { 
-  format, 
-  parse, 
-  addMinutes, 
-  differenceInMinutes, 
-  startOfDay, 
+import {
+  format,
+  parse,
+  addMinutes,
+  differenceInMinutes,
+  startOfDay,
   endOfDay,
-  setHours, 
-  setMinutes as setMins, 
-  getHours, 
-  getMinutes, 
+  setHours,
+  setMinutes as setMins,
+  getHours,
+  getMinutes,
   parseISO,
-  isValid, 
-  addDays, 
-  startOfWeek, 
-  endOfWeek, 
+  isValid,
+  addDays,
+  startOfWeek,
+  endOfWeek,
   addWeeks,
-  isSameDay
+  isSameDay,
+  getISOWeek
 } from 'date-fns';
 import {
   toZonedTime,
@@ -109,6 +110,70 @@ export class DateService {
     return this.formatDate(date);
   }
   
+  /**
+   * Format time in 12-hour format with AM/PM
+   * @param date - Date to format
+   * @returns Time string in 12-hour format (e.g., "2:30 PM")
+   */
+  public formatTime12(date: Date): string {
+    const hours = getHours(date);
+    const minutes = getMinutes(date);
+    const period = hours >= 12 ? 'PM' : 'AM';
+    const displayHours = hours % 12 || 12;
+    
+    return `${displayHours}:${String(minutes).padStart(2, '0')} ${period}`;
+  }
+  
+  /**
+   * Get day name for a date
+   * @param date - Date to get day name for
+   * @param format - 'short' (e.g., 'Mon') or 'long' (e.g., 'Monday')
+   * @returns Day name
+   */
+  public getDayName(date: Date, format: 'short' | 'long' = 'short'): string {
+    const formatter = new Intl.DateTimeFormat('en-US', {
+      weekday: format
+    });
+    return formatter.format(date);
+  }
+  
+  /**
+   * Format a date range with customizable options
+   * @param start - Start date
+   * @param end - End date
+   * @param options - Formatting options
+   * @returns Formatted date range string
+   */
+  public formatDateRange(
+    start: Date,
+    end: Date,
+    options: {
+      locale?: string;
+      month?: 'numeric' | '2-digit' | 'long' | 'short' | 'narrow';
+      day?: 'numeric' | '2-digit';
+      year?: 'numeric' | '2-digit';
+    } = {}
+  ): string {
+    const { locale = 'en-US', month = 'short', day = 'numeric' } = options;
+    
+    const startYear = start.getFullYear();
+    const endYear = end.getFullYear();
+    
+    const formatter = new Intl.DateTimeFormat(locale, {
+      month,
+      day,
+      year: startYear !== endYear ? 'numeric' : undefined
+    });
+
+    // @ts-ignore - formatRange is available in modern browsers
+    if (typeof formatter.formatRange === 'function') {
+      // @ts-ignore
+      return formatter.formatRange(start, end);
+    }
+    
+    return `${formatter.format(start)} - ${formatter.format(end)}`;
+  }
+  
   // ============================================
   // TIME CALCULATIONS
   // ============================================
@@ -193,6 +258,53 @@ export class DateService {
     return addWeeks(date, weeks);
   }
   
+  /**
+   * Get ISO week number (1-53)
+   * @param date - Date to get week number for
+   * @returns ISO week number
+   */
+  public getWeekNumber(date: Date): number {
+    return getISOWeek(date);
+  }
+  
+  /**
+   * Get all dates in a full week (7 days starting from given date)
+   * @param weekStart - Start date of the week
+   * @returns Array of 7 dates
+   */
+  public getFullWeekDates(weekStart: Date): Date[] {
+    const dates: Date[] = [];
+    for (let i = 0; i < 7; i++) {
+      dates.push(this.addDays(weekStart, i));
+    }
+    return dates;
+  }
+  
+  /**
+   * Get dates for work week using ISO 8601 day numbering (Monday=1, Sunday=7)
+   * @param weekStart - Any date in the week
+   * @param workDays - Array of ISO day numbers (1=Monday, 7=Sunday)
+   * @returns Array of dates for the specified work days
+   */
+  public getWorkWeekDates(weekStart: Date, workDays: number[]): Date[] {
+    const dates: Date[] = [];
+    
+    // Get Monday of the week
+    const weekBounds = this.getWeekBounds(weekStart);
+    const mondayOfWeek = this.startOfDay(weekBounds.start);
+    
+    // Calculate dates for each work day using ISO numbering
+    workDays.forEach(isoDay => {
+      const date = new Date(mondayOfWeek);
+      // ISO day 1=Monday is +0 days, ISO day 7=Sunday is +6 days
+      const daysFromMonday = isoDay === 7 ? 6 : isoDay - 1;
+      date.setDate(mondayOfWeek.getDate() + daysFromMonday);
+      dates.push(date);
+    });
+    
+    return dates;
+  }
+  
   // ============================================
   // GRID HELPERS
   // ============================================
@@ -290,4 +402,16 @@ export class DateService {
   public isValid(date: Date): boolean {
     return isValid(date);
   }
+  
+  /**
+   * Check if event spans multiple days
+   * @param start - Start date or ISO string
+   * @param end - End date or ISO string
+   * @returns True if spans multiple days
+   */
+  public isMultiDay(start: Date | string, end: Date | string): boolean {
+    const startDate = typeof start === 'string' ? this.parseISO(start) : start;
+    const endDate = typeof end === 'string' ? this.parseISO(end) : end;
+    return !this.isSameDay(startDate, endDate);
+  }
 }