# Date Library (date)
# Difficulty: 1
# Description: Examples of using the Date Library in Razen
## Introduction
The Date Library (`date`) provides functions for working with dates and timestamps in Razen. This library helps you get the current date, format dates, parse date strings, and perform date calculations.
## Library Overview
### Date Library Functions
- `now` → Gets the current timestamp in seconds since the Unix epoch
- `year` → Gets the current year
- `month` → Gets the current month (1-12)
- `day` → Gets the current day of month
- `format` → Formats a timestamp as a string
- `parse` → Parses a date string with a format
- `add_days` → Adds days to a timestamp
- `add_months` → Adds months to a timestamp
- `add_years` → Adds years to a timestamp
- `weekday` → Gets the day of week (0 = Sunday, 6 = Saturday)
- `weekday_name` → Gets the name of the weekday
- `days_in_month` → Gets the number of days in a month
- `is_leap_year` → Checks if a year is a leap year
- `diff_days` → Gets the difference in days between two dates
## How to Use the Date Library
### Library Import
To use the Date Library in Razen, you first need to import it using the `lib` keyword:
```razen
lib date;
```
### Function Calling
Once imported, you can call functions from the library using the double colon `::` syntax:
```razen
date::functionName(parameters);
```
**Note about bracket notation (Legacy):**
In older versions of Razen (before beta v0.1.75), you could also use bracket notation for library functions:
```razen
# DEPRECATED - Only works in Razen before beta v0.1.75
date[functionName](parameters);
```
This syntax is no longer supported in newer versions of Razen.
## Basic Examples
### Getting Current Date Information
```razen
# Import the date library
lib date;
# Get current timestamp (Unix timestamp in seconds)
num now = date::now();
show "Current timestamp: " + now; # Output: Current timestamp: 1717517400 (depends on your timezone)
# Get current year
num year = date::year();
show "Current year: " + year; # Output: Current year: 2025 (depends on current year)
# Get current month (1-12)
num month = date::month();
show "Current month: " + month; # Output: Current month: 6 (depends on current month)
# Get current day of month
num day = date::day();
show "Current day: " + day; # Output: Current day: 3 (depends on current day)
```
### Formatting Dates
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now(); # Gives a number representing the current timestamp in milliseconds since the Unix epoch.
# Format date as a string
str formatted = date::format(now, "YYYY-MM-DD"); # Format the date as a string
show "Formatted date: " + formatted; # Output: Formatted date: 2025-06-03
# Different format examples
show "Full date and time: " + date::format(now, "YYYY-MM-DD HH:mm:ss"); # Output: 2025-06-03 21:45:30
show "Short date: " + date::format(now, "MM/DD/YYYY"); # Output: 06/03/2025
show "Long date: " + date::format(now, "MM DD, YYYY"); # Output: 06 03, 2025
```
### Parsing Date Strings
```razen
# Import the date library
lib date;
# Parse a date string into a timestamp
str dateString = "2025-06-03";
num parsedTimestamp = date::parse(dateString, "YYYY-MM-DD");
show "Parsed timestamp: " + parsedTimestamp;
# Format the parsed timestamp to verify
str formatted = date::format(parsedTimestamp, "MM, DD, YYYY");
show "Formatted parsed date: " + formatted; # Output: 06, 03, 2025
# Parse different date formats
str dateString2 = "06/03/2025";
num parsedTimestamp2 = date::parse(dateString2, "MM/DD/YYYY");
show "Parsed timestamp 2: " + parsedTimestamp2;
str dateString3 = "06, 03, 2025";
num parsedTimestamp3 = date::parse(dateString3, "MM, DD, YYYY");
show "Parsed timestamp 3: " + parsedTimestamp3;
```
### Date Manipulation
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
str currentDate = date::format(now, "YYYY-MM-DD");
show "Current date: " + currentDate; # Output: Current date: 2025-06-03
# Add days to current date
num futureDate = date::add_days(now, 7);
str futureDateFormatted = date::format(futureDate, "YYYY-MM-DD");
show "Date after adding 7 days: " + futureDateFormatted; # Output: 2025-06-10
# Add months to current date
num futureMonth = date::add_months(now, 3);
str futureMonthFormatted = date::format(futureMonth, "YYYY-MM-DD");
show "Date after adding 3 months: " + futureMonthFormatted; # Output: 2025-09-03
# Add years to current date
num futureYear = date::add_years(now, 1);
str futureYearFormatted = date::format(futureYear, "YYYY-MM-DD");
show "Date after adding 1 year: " + futureYearFormatted; # Output: 2026-06-03
```
### Weekday Information
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
# Get weekday (0 = Sunday, 6 = Saturday)
num weekday = date::weekday(now);
show "Current weekday (0-6): " + weekday; # Output: Current weekday (0-6): 2 (Tuesday)
# Get weekday name
str weekdayName = date::weekday_name(now);
show "Current weekday name: " + weekdayName; # Output: Current weekday name: Tuesday
# Format date with weekday for verification
str formattedWithWeekday = date::format(now, "C_D, C_M, DD, YYYY");
show "Formatted with weekday: " + formattedWithWeekday; # Output: Tuesday, June, 03, 2025
```
### Month Information and Leap Years
```razen
# Import the date library
lib date;
# Get days in current month
num year = date::year();
num month = date::month();
num daysInMonth = date::days_in_month(year, month);
show "Days in current month (" + month + "/" + year + "): " + daysInMonth; # Output: Days in current month (6/2025): 30
# Check days in February for leap year and non-leap year
show "Days in February 2024 (leap year): " + date::days_in_month(2024, 2); # Output: 29
show "Days in February 2025 (non-leap year): " + date::days_in_month(2025, 2); # Output: 28
# Check if years are leap years
show "Is 2024 a leap year? " + date::is_leap_year(2024); # Output: true
show "Is 2025 a leap year? " + date::is_leap_year(2025); # Output: false
show "Is 2000 a leap year? " + date::is_leap_year(2000); # Output: true
show "Is 1900 a leap year? " + date::is_leap_year(1900); # Output: false
```
### Date Difference
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
# Calculate difference between dates
num futureDate = date::add_days(now, 7);
num daysDiff = date::diff_days(now, futureDate);
show "Difference in days: " + daysDiff; # Output: Difference in days: 7
# Calculate age in days
str birthdate = "1990-01-15";
num birthdateTimestamp = date::parse(birthdate, "YYYY-MM-DD");
num ageInDays = date::diff_days(birthdateTimestamp, now);
show "Age in days for someone born on " + birthdate + ": " + ageInDays;
```
## Advanced Examples
### Date Validation Function
```razen
# Import the date library
lib date;
# Function to validate if a date string is valid
fun isValidDate(dateStr, format) {
try {
# Try to parse the date string
num timestamp = date::parse(dateStr, format);
# If parsing succeeds and results in a valid timestamp
if (timestamp > 0) {
# Format the timestamp back to a date string for verification
str formatted = date::format(timestamp, format);
# Check if the formatted date matches the original date string
return formatted == dateStr;
}
return false;
} catch (err) {
# If parsing fails, the date is invalid
return false;
}
}
# Test the validation function
show "Is '2025-06-03' valid? " + isValidDate("2025-06-03", "YYYY-MM-DD"); # Output: true
show "Is '2025-02-30' valid? " + isValidDate("2025-02-30", "YYYY-MM-DD"); # Output: false (February doesn't have 30 days)
show "Is '2025-13-01' valid? " + isValidDate("2025-13-01", "YYYY-MM-DD"); # Output: false (Invalid month)
```
### Date Range Generator
```razen
# Import the date library
lib date;
# Function to generate an array of dates within a range
fun generateDateRange(startDate, endDate, format) {
# Parse start and end dates
num startTimestamp = date::parse(startDate, format);
num endTimestamp = date::parse(endDate, format);
# Check if dates are valid
if (startTimestamp <= 0 || endTimestamp <= 0) {
return "Invalid date format";
}
# Check if end date is after start date
if (startTimestamp > endTimestamp) {
return "End date must be after start date";
}
# Calculate number of days between dates
num daysDiff = date::diff_days(startTimestamp, endTimestamp);
# Generate array of dates
str dates = [];
for (num i = 0; i <= daysDiff; i = i + 1) {
num currentTimestamp = date::add_days(startTimestamp, i);
str currentDate = date::format(currentTimestamp, format);
dates.push(currentDate);
}
return dates;
}
# Generate a range of dates
str dateRange = generateDateRange("2025-06-01", "2025-06-07", "YYYY-MM-DD");
show "Date range: " + dateRange;
# Output: Date range: ["2025-06-01", "2025-06-02", "2025-06-03", "2025-06-04", "2025-06-05", "2025-06-06", "2025-06-07"]
```
### Age Calculator
```razen
# Import the date library
lib date;
# Function to calculate age in years, months, and days
fun calculateAge(birthdate, format) {
# Parse birthdate
num birthdateTimestamp = date::parse(birthdate, format);
# Get current timestamp
num now = date::now();
# Extract birth year, month, and day
num birthYear = date::year(birthdateTimestamp);
num birthMonth = date::month(birthdateTimestamp);
num birthDay = date::day(birthdateTimestamp);
# Extract current year, month, and day
num currentYear = date::year(now);
num currentMonth = date::month(now);
num currentDay = date::day(now);
# Calculate age in years
num years = currentYear - birthYear;
# Adjust years if birthday hasn't occurred this year yet
if (currentMonth < birthMonth || (currentMonth == birthMonth && currentDay < birthDay)) {
years = years - 1;
}
# Calculate months
num months = currentMonth - birthMonth;
if (months < 0) {
months = months + 12;
}
# Adjust months if day of month hasn't occurred yet
if (currentDay < birthDay) {
months = months - 1;
if (months < 0) {
months = months + 12;
}
}
# Calculate days
num days = currentDay - birthDay;
if (days < 0) {
# Get days in previous month
num prevMonth = currentMonth - 1;
if (prevMonth == 0) {
prevMonth = 12;
years = years - 1;
}
days = days + date::days_in_month(currentYear, prevMonth);
}
# Create result object
map result = {
"years": years,
"months": months,
"days": days,
"totalDays": date::diff_days(birthdateTimestamp, now)
};
return result;
}
# Calculate age for a birthdate
str birthdate = "1990-05-15";
map age = calculateAge(birthdate, "YYYY-MM-DD");
show "Age for someone born on " + birthdate + ":";
show "Years: " + age["years"];
show "Months: " + age["months"];
show "Days: " + age["days"];
show "Total days: " + age["totalDays"];
```
## Practical Application: Event Scheduler
```razen
# Import the date library
lib date;
# Simple event scheduler application
class EventScheduler {
# Constructor
init() {
this.events = [];
}
# Add a new event
fun addEvent(str title, str eventDate, str description) {
# Parse event date
num eventTimestamp = date::parse(eventDate, "YYYY-MM-DD");
# Validate date
if (eventTimestamp <= 0) {
return "Invalid date format. Please use YYYY-MM-DD.";
}
# Create event object
map event = {
"id": this.events.length + 1,
"title": title,
"date": eventDate,
"timestamp": eventTimestamp,
"description": description,
"weekday": date::weekday_name(eventTimestamp)
};
# Add to events array
this.events.push(event);
return "Event '" + title + "' scheduled for " + eventDate + " (" + event["weekday"] + ")";
}
# Get all events
fun getAllEvents() {
return this.events;
}
# Get events for a specific date
fun getEventsByDate(str eventDate) {
str filteredEvents = [];
for (num i = 0; i < this.events.length; i = i + 1) {
if (this.events[i]["date"] == eventDate) {
filteredEvents.push(this.events[i]);
}
}
return filteredEvents;
}
# Get upcoming events
fun getUpcomingEvents(num days) {
# Get current timestamp
num now = date::now();
# Calculate end date
num endTimestamp = date::add_days(now, days);
# Filter upcoming events
str upcomingEvents = [];
for (num i = 0; i < this.events.length; i = i + 1) {
num eventTimestamp = this.events[i]["timestamp"];
if (eventTimestamp >= now && eventTimestamp <= endTimestamp) {
# Add days until event
num daysUntil = date::diff_days(now, eventTimestamp);
map event = this.events[i];
event["daysUntil"] = daysUntil;
upcomingEvents.push(event);
}
}
return upcomingEvents;
}
# Display events in a formatted way
fun displayEvents(str events) {
if (events.length == 0) {
return "No events found.";
}
str result = "=== Events ===\n";
for (num i = 0; i < events.length; i = i + 1) {
map event = events[i];
result = result + "ID: " + event["id"] + "\n";
result = result + "Title: " + event["title"] + "\n";
result = result + "Date: " + event["date"] + " (" + event["weekday"] + ")\n";
if (event["daysUntil"] != null) {
result = result + "Days until event: " + event["daysUntil"] + "\n";
}
result = result + "Description: " + event["description"] + "\n\n";
}
return result;
}
}
# Create a new scheduler
EventScheduler scheduler = new EventScheduler();
# Add events
show scheduler.addEvent("Team Meeting", "2025-06-10", "Weekly team sync-up");
show scheduler.addEvent("Project Deadline", "2025-06-15", "Final project submission");
show scheduler.addEvent("Conference", "2025-07-05", "Annual industry conference");
show scheduler.addEvent("Birthday Party", "2025-06-20", "John's birthday celebration");
# Display all events
show scheduler.displayEvents(scheduler.getAllEvents());
# Display events for a specific date
show "Events on 2025-06-15:";
show scheduler.displayEvents(scheduler.getEventsByDate("2025-06-15"));
# Display upcoming events in the next 14 days
show "Upcoming events in the next 14 days:";
show scheduler.displayEvents(scheduler.getUpcomingEvents(14));
```
## Summary
The Date Library in Razen provides essential functions for working with dates:
- Getting current date information (`now`, `year`, `month`, `day`)
- Formatting and parsing dates (`format`, `parse`)
- Date manipulation (`add_days`, `add_months`, `add_years`)
- Weekday information (`weekday`, `weekday_name`)
- Month and leap year utilities (`days_in_month`, `is_leap_year`)
- Date difference calculation (`diff_days`)
These functions help you work with dates efficiently in your Razen programs.
# Date Library (date)
# Difficulty: 1
# Description: Examples of using the Date Library in Razen
## Introduction
The Date Library (`date`) provides functions for working with dates and timestamps in Razen. This library helps you get the current date, format dates, parse date strings, and perform date calculations.
## Library Overview
### Date Library Functions
- `now` → Gets the current timestamp in seconds since the Unix epoch
- `year` → Gets the current year
- `month` → Gets the current month (1-12)
- `day` → Gets the current day of month
- `format` → Formats a timestamp as a string
- `parse` → Parses a date string with a format
- `add_days` → Adds days to a timestamp
- `add_months` → Adds months to a timestamp
- `add_years` → Adds years to a timestamp
- `weekday` → Gets the day of week (0 = Sunday, 6 = Saturday)
- `weekday_name` → Gets the name of the weekday
- `days_in_month` → Gets the number of days in a month
- `is_leap_year` → Checks if a year is a leap year
- `diff_days` → Gets the difference in days between two dates
## How to Use the Date Library
### Library Import
To use the Date Library in Razen, you first need to import it using the `lib` keyword:
```razen
lib date;
```
### Function Calling
Once imported, you can call functions from the library using the double colon `::` syntax:
```razen
date::functionName(parameters);
```
**Note about bracket notation (Legacy):**
In older versions of Razen (before beta v0.1.75), you could also use bracket notation for library functions:
```razen
# DEPRECATED - Only works in Razen before beta v0.1.75
date[functionName](parameters);
```
This syntax is no longer supported in newer versions of Razen.
## Basic Examples
### Getting Current Date Information
```razen
# Import the date library
lib date;
# Get current timestamp (Unix timestamp in seconds)
num now = date::now();
show "Current timestamp: " + now; # Output: Current timestamp: 1717517400 (depends on your timezone)
# Get current year
num year = date::year();
show "Current year: " + year; # Output: Current year: 2025 (depends on current year)
# Get current month (1-12)
num month = date::month();
show "Current month: " + month; # Output: Current month: 6 (depends on current month)
# Get current day of month
num day = date::day();
show "Current day: " + day; # Output: Current day: 3 (depends on current day)
```
### Formatting Dates
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now(); # Gives a number representing the current timestamp in milliseconds since the Unix epoch.
# Format date as a string
str formatted = date::format(now, "YYYY-MM-DD"); # Format the date as a string
show "Formatted date: " + formatted; # Output: Formatted date: 2025-06-03
# Different format examples
show "Full date and time: " + date::format(now, "YYYY-MM-DD HH:mm:ss"); # Output: 2025-06-03 21:45:30
show "Short date: " + date::format(now, "MM/DD/YYYY"); # Output: 06/03/2025
show "Long date: " + date::format(now, "MM DD, YYYY"); # Output: 06 03, 2025
```
### Parsing Date Strings
```razen
# Import the date library
lib date;
# Parse a date string into a timestamp
str dateString = "2025-06-03";
num parsedTimestamp = date::parse(dateString, "YYYY-MM-DD");
show "Parsed timestamp: " + parsedTimestamp;
# Format the parsed timestamp to verify
str formatted = date::format(parsedTimestamp, "MM, DD, YYYY");
show "Formatted parsed date: " + formatted; # Output: 06, 03, 2025
# Parse different date formats
str dateString2 = "06/03/2025";
num parsedTimestamp2 = date::parse(dateString2, "MM/DD/YYYY");
show "Parsed timestamp 2: " + parsedTimestamp2;
str dateString3 = "06, 03, 2025";
num parsedTimestamp3 = date::parse(dateString3, "MM, DD, YYYY");
show "Parsed timestamp 3: " + parsedTimestamp3;
```
### Date Manipulation
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
str currentDate = date::format(now, "YYYY-MM-DD");
show "Current date: " + currentDate; # Output: Current date: 2025-06-03
# Add days to current date
num futureDate = date::add_days(now, 7);
str futureDateFormatted = date::format(futureDate, "YYYY-MM-DD");
show "Date after adding 7 days: " + futureDateFormatted; # Output: 2025-06-10
# Add months to current date
num futureMonth = date::add_months(now, 3);
str futureMonthFormatted = date::format(futureMonth, "YYYY-MM-DD");
show "Date after adding 3 months: " + futureMonthFormatted; # Output: 2025-09-03
# Add years to current date
num futureYear = date::add_years(now, 1);
str futureYearFormatted = date::format(futureYear, "YYYY-MM-DD");
show "Date after adding 1 year: " + futureYearFormatted; # Output: 2026-06-03
```
### Weekday Information
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
# Get weekday (0 = Sunday, 6 = Saturday)
num weekday = date::weekday(now);
show "Current weekday (0-6): " + weekday; # Output: Current weekday (0-6): 2 (Tuesday)
# Get weekday name
str weekdayName = date::weekday_name(now);
show "Current weekday name: " + weekdayName; # Output: Current weekday name: Tuesday
# Format date with weekday for verification
str formattedWithWeekday = date::format(now, "C_D, C_M, DD, YYYY");
show "Formatted with weekday: " + formattedWithWeekday; # Output: Tuesday, June, 03, 2025
```
### Month Information and Leap Years
```razen
# Import the date library
lib date;
# Get days in current month
num year = date::year();
num month = date::month();
num daysInMonth = date::days_in_month(year, month);
show "Days in current month (" + month + "/" + year + "): " + daysInMonth; # Output: Days in current month (6/2025): 30
# Check days in February for leap year and non-leap year
show "Days in February 2024 (leap year): " + date::days_in_month(2024, 2); # Output: 29
show "Days in February 2025 (non-leap year): " + date::days_in_month(2025, 2); # Output: 28
# Check if years are leap years
show "Is 2024 a leap year? " + date::is_leap_year(2024); # Output: true
show "Is 2025 a leap year? " + date::is_leap_year(2025); # Output: false
show "Is 2000 a leap year? " + date::is_leap_year(2000); # Output: true
show "Is 1900 a leap year? " + date::is_leap_year(1900); # Output: false
```
### Date Difference
```razen
# Import the date library
lib date;
# Get current timestamp
num now = date::now();
# Calculate difference between dates
num futureDate = date::add_days(now, 7);
num daysDiff = date::diff_days(now, futureDate);
show "Difference in days: " + daysDiff; # Output: Difference in days: 7
# Calculate age in days
str birthdate = "1990-01-15";
num birthdateTimestamp = date::parse(birthdate, "YYYY-MM-DD");
num ageInDays = date::diff_days(birthdateTimestamp, now);
show "Age in days for someone born on " + birthdate + ": " + ageInDays;
```
## Advanced Examples
### Date Validation Function
```razen
# Import the date library
lib date;
# Function to validate if a date string is valid
fun isValidDate(dateStr, format) {
try {
# Try to parse the date string
num timestamp = date::parse(dateStr, format);
# If parsing succeeds and results in a valid timestamp
if (timestamp > 0) {
# Format the timestamp back to a date string for verification
str formatted = date::format(timestamp, format);
# Check if the formatted date matches the original date string
return formatted == dateStr;
}
return false;
} catch (err) {
# If parsing fails, the date is invalid
return false;
}
}
# Test the validation function
show "Is '2025-06-03' valid? " + isValidDate("2025-06-03", "YYYY-MM-DD"); # Output: true
show "Is '2025-02-30' valid? " + isValidDate("2025-02-30", "YYYY-MM-DD"); # Output: false (February doesn't have 30 days)
show "Is '2025-13-01' valid? " + isValidDate("2025-13-01", "YYYY-MM-DD"); # Output: false (Invalid month)
```
### Date Range Generator
```razen
# Import the date library
lib date;
# Function to generate an array of dates within a range
fun generateDateRange(startDate, endDate, format) {
# Parse start and end dates
num startTimestamp = date::parse(startDate, format);
num endTimestamp = date::parse(endDate, format);
# Check if dates are valid
if (startTimestamp <= 0 || endTimestamp <= 0) {
return "Invalid date format";
}
# Check if end date is after start date
if (startTimestamp > endTimestamp) {
return "End date must be after start date";
}
# Calculate number of days between dates
num daysDiff = date::diff_days(startTimestamp, endTimestamp);
# Generate array of dates
str dates = [];
for (num i = 0; i <= daysDiff; i = i + 1) {
num currentTimestamp = date::add_days(startTimestamp, i);
str currentDate = date::format(currentTimestamp, format);
dates.push(currentDate);
}
return dates;
}
# Generate a range of dates
str dateRange = generateDateRange("2025-06-01", "2025-06-07", "YYYY-MM-DD");
show "Date range: " + dateRange;
# Output: Date range: ["2025-06-01", "2025-06-02", "2025-06-03", "2025-06-04", "2025-06-05", "2025-06-06", "2025-06-07"]
```
### Age Calculator
```razen
# Import the date library
lib date;
# Function to calculate age in years, months, and days
fun calculateAge(birthdate, format) {
# Parse birthdate
num birthdateTimestamp = date::parse(birthdate, format);
# Get current timestamp
num now = date::now();
# Extract birth year, month, and day
num birthYear = date::year(birthdateTimestamp);
num birthMonth = date::month(birthdateTimestamp);
num birthDay = date::day(birthdateTimestamp);
# Extract current year, month, and day
num currentYear = date::year(now);
num currentMonth = date::month(now);
num currentDay = date::day(now);
# Calculate age in years
num years = currentYear - birthYear;
# Adjust years if birthday hasn't occurred this year yet
if (currentMonth < birthMonth || (currentMonth == birthMonth && currentDay < birthDay)) {
years = years - 1;
}
# Calculate months
num months = currentMonth - birthMonth;
if (months < 0) {
months = months + 12;
}
# Adjust months if day of month hasn't occurred yet
if (currentDay < birthDay) {
months = months - 1;
if (months < 0) {
months = months + 12;
}
}
# Calculate days
num days = currentDay - birthDay;
if (days < 0) {
# Get days in previous month
num prevMonth = currentMonth - 1;
if (prevMonth == 0) {
prevMonth = 12;
years = years - 1;
}
days = days + date::days_in_month(currentYear, prevMonth);
}
# Create result object
map result = {
"years": years,
"months": months,
"days": days,
"totalDays": date::diff_days(birthdateTimestamp, now)
};
return result;
}
# Calculate age for a birthdate
str birthdate = "1990-05-15";
map age = calculateAge(birthdate, "YYYY-MM-DD");
show "Age for someone born on " + birthdate + ":";
show "Years: " + age["years"];
show "Months: " + age["months"];
show "Days: " + age["days"];
show "Total days: " + age["totalDays"];
```
## Practical Application: Event Scheduler
```razen
# Import the date library
lib date;
# Simple event scheduler application
class EventScheduler {
# Constructor
init() {
this.events = [];
}
# Add a new event
fun addEvent(str title, str eventDate, str description) {
# Parse event date
num eventTimestamp = date::parse(eventDate, "YYYY-MM-DD");
# Validate date
if (eventTimestamp <= 0) {
return "Invalid date format. Please use YYYY-MM-DD.";
}
# Create event object
map event = {
"id": this.events.length + 1,
"title": title,
"date": eventDate,
"timestamp": eventTimestamp,
"description": description,
"weekday": date::weekday_name(eventTimestamp)
};
# Add to events array
this.events.push(event);
return "Event '" + title + "' scheduled for " + eventDate + " (" + event["weekday"] + ")";
}
# Get all events
fun getAllEvents() {
return this.events;
}
# Get events for a specific date
fun getEventsByDate(str eventDate) {
str filteredEvents = [];
for (num i = 0; i < this.events.length; i = i + 1) {
if (this.events[i]["date"] == eventDate) {
filteredEvents.push(this.events[i]);
}
}
return filteredEvents;
}
# Get upcoming events
fun getUpcomingEvents(num days) {
# Get current timestamp
num now = date::now();
# Calculate end date
num endTimestamp = date::add_days(now, days);
# Filter upcoming events
str upcomingEvents = [];
for (num i = 0; i < this.events.length; i = i + 1) {
num eventTimestamp = this.events[i]["timestamp"];
if (eventTimestamp >= now && eventTimestamp <= endTimestamp) {
# Add days until event
num daysUntil = date::diff_days(now, eventTimestamp);
map event = this.events[i];
event["daysUntil"] = daysUntil;
upcomingEvents.push(event);
}
}
return upcomingEvents;
}
# Display events in a formatted way
fun displayEvents(str events) {
if (events.length == 0) {
return "No events found.";
}
str result = "=== Events ===\n";
for (num i = 0; i < events.length; i = i + 1) {
map event = events[i];
result = result + "ID: " + event["id"] + "\n";
result = result + "Title: " + event["title"] + "\n";
result = result + "Date: " + event["date"] + " (" + event["weekday"] + ")\n";
if (event["daysUntil"] != null) {
result = result + "Days until event: " + event["daysUntil"] + "\n";
}
result = result + "Description: " + event["description"] + "\n\n";
}
return result;
}
}
# Create a new scheduler
EventScheduler scheduler = new EventScheduler();
# Add events
show scheduler.addEvent("Team Meeting", "2025-06-10", "Weekly team sync-up");
show scheduler.addEvent("Project Deadline", "2025-06-15", "Final project submission");
show scheduler.addEvent("Conference", "2025-07-05", "Annual industry conference");
show scheduler.addEvent("Birthday Party", "2025-06-20", "John's birthday celebration");
# Display all events
show scheduler.displayEvents(scheduler.getAllEvents());
# Display events for a specific date
show "Events on 2025-06-15:";
show scheduler.displayEvents(scheduler.getEventsByDate("2025-06-15"));
# Display upcoming events in the next 14 days
show "Upcoming events in the next 14 days:";
show scheduler.displayEvents(scheduler.getUpcomingEvents(14));
```
## Summary
The Date Library in Razen provides essential functions for working with dates:
- Getting current date information (`now`, `year`, `month`, `day`)
- Formatting and parsing dates (`format`, `parse`)
- Date manipulation (`add_days`, `add_months`, `add_years`)
- Weekday information (`weekday`, `weekday_name`)
- Month and leap year utilities (`days_in_month`, `is_leap_year`)
- Date difference calculation (`diff_days`)
These functions help you work with dates efficiently in your Razen programs.
