@keerthana_lagadapati/date-utilities/README.md

The Date Utilities Module provides a collection of reusable functions to simplify working with dates in JavaScript.

# Date Utilities Module

The **Date Utilities Module** provides a collection of reusable functions to simplify working with dates in JavaScript. It is lightweight, consistent, and highly useful for a wide range of applications, including MERN stack projects.

---


## Features

1. **Date Formatting**: Convert date objects into specific string formats (e.g., `DD-MM-YYYY`).
2. **Add/Subtract Days**: Easily manipulate date objects by adding or subtracting days.
3. **Leap Year Check**: Determine if a given year is a leap year.
4. **Weekday Names**: Retrieve the weekday name for any date.
5. **Day Difference Calculation**: Calculate the difference in days between two dates.
6. **Weekend Check**: Check if a given date falls on a weekend.

---


## Installation

To use the **Date Utilities Module** in your project, install it via npm:

```bash
npm install @keerthana_lagadapati/date-utilities
```

---


## Usage

### Importing the Module

```javascript
import DateUtils from '@keerthana_lagadapati/date-utilities';
```

### Available Functions

#### 1. `formatDate(date, format)`
Formats a date object into a specified format.

**Parameters:**
- `date`: The date object to format.
- `format`: The desired string format (default: `"DD-MM-YYYY"`).

**Example:**
```javascript
const today = new Date();
console.log(DateUtils.formatDate(today, "DD/MM/YYYY")); // Output: e.g., 28/01/2025
```

---


#### 2. `addDays(date, days)`
Adds a specified number of days to a date object.

**Parameters:**
- `date`: The base date object.
- `days`: The number of days to add.

**Example:**
```javascript
const today = new Date();
console.log(DateUtils.addDays(today, 5)); // Output: Date 5 days from today
```

---


#### 3. `subtractDays(date, days)`
Subtracts a specified number of days from a date object.

**Parameters:**
- `date`: The base date object.
- `days`: The number of days to subtract.

**Example:**
```javascript
const today = new Date();
console.log(DateUtils.subtractDays(today, 5)); // Output: Date 5 days ago
```

---


#### 4. `isLeapYear(year)`
Checks if a given year is a leap year.

**Parameters:**
- `year`: The year to check.

**Example:**
```javascript
console.log(DateUtils.isLeapYear(2024)); // Output: true
```

---


#### 5. `getWeekday(date)`
Returns the weekday name for a given date.

**Parameters:**
- `date`: The date object to evaluate.

**Example:**
```javascript
const today = new Date();
console.log(DateUtils.getWeekday(today)); // Output: e.g., "Monday"
```

---


#### 6. `daysBetween(date1, date2)`
Calculates the number of days between two dates.

**Parameters:**
- `date1`: The first date.
- `date2`: The second date.

**Example:**
```javascript
const date1 = new Date('2025-01-01');
const date2 = new Date('2025-01-10');
console.log(DateUtils.daysBetween(date1, date2)); // Output: 9
```

---


#### 7. `isWeekend(date)`
Checks if a date falls on a weekend.

**Parameters:**
- `date`: The date object to evaluate.

**Example:**
```javascript
const today = new Date();
console.log(DateUtils.isWeekend(today)); // Output: true or false
```

---


## Use Cases

### 1. Task or Event Management
- **Use Case**: For a task management system or event scheduler, `addDays` and `formatDate` can help set deadlines or display events in a human-readable format.
- **Example**: Automatically calculate and display task due dates.

### 2. User-Friendly Timestamps
- **Use Case**: Display user activity logs (e.g., "Last login: 12-Jan-2025").
- **Example**: Use `formatDate` to show user activity in readable formats in the front-end.

### 3. Reminder System
- **Use Case**: Schedule reminders for users (e.g., reminders for upcoming appointments or renewals).
- **Example**: Use `addDays` to calculate future reminders and `daysBetween` to determine how soon reminders should be sent.

### 4. Analytics Dashboard
- **Use Case**: Display trends over time (e.g., daily active users or revenue growth).
- **Example**: Use `daysBetween` to calculate date ranges for analytics queries.

### 5. Content Expiry Handling
- **Use Case**: Automatically expire content after a certain period (e.g., temporary posts or promotional offers).
- **Example**: Use `subtractDays` to calculate content expiry dates in both front-end and back-end.

### 6. Localization of Weekdays
- **Use Case**: Display localized weekday names in a calendar component.
- **Example**: Use `getWeekday` for a user-friendly calendar in the front-end.

### 7. Leap Year Logic
- **Use Case**: Handle leap-year scenarios for billing cycles or subscription periods.
- **Example**: Use `isLeapYear` to accurately calculate yearly plans.