Accurate Conversion Between Gregorian and Hebrew Calendars
Gregorian to Hebrew Date Converter
January
February
March
April
May
June
July
August
September
October
November
December
Hebrew to Gregorian Date Converter
Tishrei
Cheshvan
Kislev
Tevet
Shevat
Adar I (in leap year)
Adar II (in leap year) / Adar (in common year)
Nisan
Iyar
Sivan
Tammuz
Av
Elul
Conversion Results
—
—
—
—
Formula Explanation: This calculator uses complex algorithms based on astronomical calculations and historical data to accurately convert between the Gregorian and Hebrew calendars. The Hebrew calendar is a lunisolar calendar, meaning it tracks both the moon's phases and the sun's position, requiring intricate adjustments for leap years and seasonal alignment.
Gregorian vs. Hebrew Year Comparison
A visual comparison of Gregorian and Hebrew year progression.
Hebrew Month Lengths (Common Year)
Hebrew Month
Number of Days
Tishrei
30
Cheshvan
29
Kislev
30
Tevet
29
Shevat
30
Adar
29
Nisan
30
Iyar
29
Sivan
30
Tammuz
29
Av
30
Elul
29
What is the Hebrew Date Calculator?
The Hebrew Date Calculator is a specialized digital tool designed to accurately convert dates between the Gregorian calendar (the internationally recognized civil calendar) and the Hebrew calendar (also known as the Jewish calendar). This lunisolar calendar is used for religious observances, holidays, and historical dating within Judaism. Understanding the Hebrew date is crucial for celebrating Jewish holidays at the correct time, observing yahrzeits (anniversaries of a death), and comprehending historical Jewish events. The calculator simplifies this process, eliminating the need for complex manual calculations or extensive tables.
Who Should Use It?
Anyone with a connection to Jewish life or history can benefit from a Hebrew Date Calculator. This includes:
Individuals celebrating Jewish holidays like Passover, Rosh Hashanah, Yom Kippur, and Hanukkah.
People observing Jewish lifecycle events such as Bar/Bat Mitzvahs or weddings.
Families tracking yahrzeits for departed loved ones.
Students and researchers studying Jewish history, culture, or religious texts.
Anyone curious about the relationship between the two calendar systems.
Common Misconceptions
A common misconception is that the Hebrew calendar is purely lunar. While it follows lunar cycles for its months, it is actually a lunisolar calendar. To keep the holidays aligned with the seasons (which are determined by the solar year), an extra month (Adar II) is added in specific years within a 19-year cycle. Another misconception is that the Hebrew year count starts from creation in a way that directly maps to Gregorian years; the Hebrew year 5784, for instance, began in September 2023. Our Hebrew Date Calculator helps clarify these nuances.
Hebrew Date Calculator Formula and Mathematical Explanation
The conversion between the Gregorian and Hebrew calendars is complex due to their fundamentally different structures. The Gregorian calendar is a purely solar calendar, while the Hebrew calendar is lunisolar. The core challenge lies in synchronizing these two systems.
Derivation and Logic
The Hebrew calendar's structure is based on the following principles:
Lunar Months: Each month begins with the new moon. Months alternate between 29 and 30 days (e.g., Tishrei has 30 days, Cheshvan has 29).
Solar Year Alignment: To ensure holidays remain in their designated seasons (e.g., Passover in spring), a leap month (Adar II) is added seven times within a 19-year cycle (Metonic cycle). This occurs in Hebrew years 3, 6, 8, 11, 14, 17, and 19.
Year Length: A common Hebrew year has 354 days (12 lunar months). A leap year has 384 days (13 lunar months). The length of Cheshvan and Kislev can vary (29 or 30 days) to prevent certain holidays from falling on specific days of the week, leading to "deficient" (353 days), "regular" (354 days), or "complete" (355 days) common years, and similarly for leap years.
Epoch: The Hebrew calendar epoch (Year 1) is traditionally dated from the creation of the world, calculated to be 3761 BCE.
The conversion process involves calculating the number of days elapsed since a common reference point (often the Gregorian epoch) and then determining the corresponding Hebrew date based on the Hebrew calendar's rules. This requires sophisticated algorithms that account for leap years in both systems, the specific day-of-week constraints for Hebrew holidays, and the precise lengths of Hebrew months.
Variables Table
Variable
Meaning
Unit
Typical Range
Gregorian Year (GY)
The year in the Gregorian calendar.
Year
1 CE – Present (or future)
Gregorian Month (GM)
The month in the Gregorian calendar.
Month (1-12)
1 – 12
Gregorian Day (GD)
The day in the Gregorian calendar.
Day (1-31)
1 – 31 (depending on month/year)
Hebrew Year (HY)
The year in the Hebrew calendar.
Year
1 AM – Present (approx. 3761 BCE onwards)
Hebrew Month (HM)
The month in the Hebrew calendar.
Month (1-13)
1 – 13 (Adar I/II in leap years)
Hebrew Day (HD)
The day in the Hebrew calendar.
Day (1-30)
1 – 30 (depending on month)
Leap Year Cycle
Determines if a Hebrew year receives an extra month (Adar II).
Cycle Position (1-19)
1 – 19
The Hebrew Date Calculator automates these intricate calculations, providing instant results.
Practical Examples (Real-World Use Cases)
Here are practical examples demonstrating the use of the Hebrew Date Calculator:
Example 1: Finding the Hebrew Date for a Birthday
Scenario: Sarah's birthday is on March 15, 2024. She wants to know the corresponding Hebrew date to celebrate her Jewish birthday.
Inputs:
Gregorian Year: 2024
Gregorian Month: March
Gregorian Day: 15
Using the Calculator: Inputting these values into the Gregorian to Hebrew converter yields:
Outputs:
Primary Result: 6 Nisan, 5784
Intermediate Value 1: Hebrew Year 5784 (a leap year)
Intermediate Value 2: Month Nisan (8th month)
Intermediate Value 3: Day 6
Interpretation: Sarah's birthday falls on the 6th day of the month of Nisan in the Hebrew year 5784. This date is significant as it precedes Passover.
Example 2: Determining the Gregorian Date of a Yahrzeit
Scenario: David's grandfather passed away on 10 Cheshvan, 5770. David wants to know the Gregorian date for the upcoming Yahrzeit.
Inputs:
Hebrew Year: 5770
Hebrew Month: Cheshvan
Hebrew Day: 10
Using the Calculator: Inputting these values into the Hebrew to Gregorian converter yields:
Outputs:
Primary Result: October 28, 2009
Intermediate Value 1: Hebrew Year 5770 (a common year)
Intermediate Value 2: Month Cheshvan (2nd month)
Intermediate Value 3: Day 10
Interpretation: The Yahrzeit for David's grandfather falls on October 28th each year. The calculator shows the original Gregorian date of passing (Oct 28, 2009) and allows for tracking subsequent Yahrzeit dates by inputting the current Hebrew year.
These examples highlight the practical utility of the Hebrew Date Calculator for personal and religious observance.
How to Use This Hebrew Date Calculator
Using our Hebrew Date Calculator is straightforward. Follow these simple steps:
Step-by-Step Instructions
Choose Conversion Direction: Decide whether you need to convert from Gregorian to Hebrew or Hebrew to Gregorian.
Enter Input Date:
Gregorian to Hebrew: Enter the Year, select the Month from the dropdown, and enter the Day.
Hebrew to Gregorian: Enter the Hebrew Year, select the Hebrew Month from the dropdown, and enter the Hebrew Day. Be mindful of leap year months (Adar I and Adar II).
Click 'Convert': Press the 'Convert' button corresponding to your chosen direction.
View Results: The calculator will display the converted date as the primary result, along with key intermediate values and a brief explanation.
Copy Results (Optional): If you need to save or share the results, click the 'Copy Results' button. This will copy the main result, intermediate values, and assumptions to your clipboard.
Reset Form: To start a new conversion, click the 'Reset' button to clear the input fields and return them to default values.
How to Read Results
Primary Result: This is the main converted date (e.g., "6 Nisan, 5784" or "October 28, 2009").
Intermediate Values: These provide context, such as the Hebrew year type (leap/common), month number, or day number.
Formula Explanation: Offers insight into the calculation logic.
Decision-Making Guidance
Use the results to plan for Jewish holidays, mark important dates like Yahrzeits or birthdays according to the Hebrew calendar, or verify historical dates. For instance, knowing the Hebrew date helps ensure you observe holidays like Sukkot or Shavuot on the correct day each year.
Key Factors That Affect Hebrew Date Results
While the conversion seems simple, several underlying factors influence the accuracy and interpretation of Hebrew date calculations:
Lunisolar Nature: The core complexity arises from the Hebrew calendar being lunisolar. Unlike the purely solar Gregorian calendar, its months are tied to lunar cycles. Adjustments (adding a leap month) are necessary to keep it synchronized with the solar year and seasons. This is the primary reason for the intricate algorithms used by the Hebrew Date Calculator.
Leap Year System (Metonic Cycle): The 19-year cycle with 7 leap years is crucial. A leap year adds Adar II, shifting all subsequent dates within that Hebrew year compared to a common year. Incorrectly identifying a leap year will lead to significant date discrepancies.
Variable Month Lengths: While most Hebrew months have fixed lengths (29 or 30 days), Cheshvan and Kislev can vary. This variation (29 or 30 days) is used to prevent certain holidays from coinciding with specific days of the week, which can slightly alter the total number of days in a common or leap year.
Epoch Difference: The Hebrew calendar's starting point (Anno Mundi, AM) is approximately 3761 BCE, while the Gregorian calendar starts at 1 CE. The significant difference in epoch requires careful calculation of elapsed days over millennia.
Daylight Saving Time (DST) & Time Zones: While DST primarily affects the Gregorian calendar's timekeeping, the exact moment a new Hebrew day begins (at sunset) can be influenced by local sunset times, which vary by longitude and season. Most calculators assume a standard sunset calculation for the conversion.
Calendar Reforms & Historical Accuracy: The Hebrew calendar was formally codified by Hillel II in the 4th century CE. Before that, months were determined by observation. Modern calculators rely on the codified system, assuming its consistent application.
Frequently Asked Questions (FAQ)
Q1: What is the difference between the Hebrew and Gregorian calendars?
A1: The Gregorian calendar is a solar calendar with 365 days (366 in leap years), used globally for civil purposes. The Hebrew calendar is lunisolar, based on lunar months but adjusted with leap months to align with solar seasons, used for Jewish religious observances and holidays. Our Hebrew Date Calculator bridges this difference.
Q2: How do I know if a Hebrew year is a leap year?
A2: A Hebrew year is a leap year if it falls on the 3rd, 6th, 8th, 11th, 14th, 17th, or 19th year of the 19-year Metonic cycle. These years have an extra month, Adar II.
Q3: Why do some Hebrew months have variable lengths?
A3: The months of Cheshvan and Kislev can have 29 or 30 days. This variability is called "Dechiyah" (postponement) and is used to ensure that certain Jewish holidays do not fall on days of the week that would lead to logistical or religious complications.
Q4: When does the Hebrew year begin?
A4: The main civil start of the Hebrew year is Rosh Hashanah, which falls on 1 Tishrei. This typically occurs in September in the Gregorian calendar. The year count begins from the traditional date of creation (Anno Mundi).
Q5: Can the calculator convert dates far in the past or future?
A5: Yes, the algorithms used are designed to handle conversions for a wide range of historical and future dates within the established parameters of both calendar systems.
Q6: What does "Yahrzeit" mean?
A6: Yahrzeit is the anniversary of a death, observed according to the Hebrew calendar date. It's a time for remembrance and prayer.
Q7: How accurate is the Hebrew Date Calculator?
A7: This calculator uses standard algorithms for lunisolar calendar conversion, providing high accuracy for dates after the formal codification of the Hebrew calendar (around 359 CE). For dates prior to that, historical records might vary.
Q8: What is the significance of the Hebrew calendar's lunisolar nature?
A8: It ensures that holidays tied to seasons (like Passover in spring) occur at the correct time of year, while still maintaining the rhythm of lunar months for other observances.
Calculate candle lighting and Havdalah times for your location.
var chartInstance = null;
function isValidGregorianDate(year, month, day) {
if (isNaN(year) || year 9999) return false;
if (isNaN(month) || month 12) return false;
if (isNaN(day) || day < 1) return false;
var daysInMonth = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
if ((year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0)) {
daysInMonth[2] = 29; // Leap year
}
return day <= daysInMonth[month];
}
function isValidHebrewDate(year, month, day) {
if (isNaN(year) || year 9999) return false;
if (isNaN(month) || month 13) return false;
if (isNaN(day) || day < 1) return false;
var maxDays = [0, 30, 30, 30, 29, 30, 30, 30, 30, 30, 29, 30, 29, 30]; // Default lengths, Adar I/II adjusted later
if (month === 7) { // Adar in common year
maxDays[7] = 29;
} else if (month === 6) { // Adar I in leap year
maxDays[6] = 30;
} else if (month === 7) { // Adar II in leap year
maxDays[7] = 29;
}
// Adjust for variable months Cheshvan and Kislev based on year type
var isLeap = (year % 19 === 3 || year % 19 === 6 || year % 19 === 8 || year % 19 === 11 || year % 19 === 14 || year % 19 === 17 || year % 19 === 0);
if (isLeap) {
if (month === 2) maxDays[2] = 30; // Cheshvan is 30 in leap years
if (month === 3) maxDays[3] = 29; // Kislev is 29 in leap years
} else {
if (month === 2) maxDays[2] = 29; // Cheshvan is 29 in common years
if (month === 3) maxDays[3] = 30; // Kislev is 30 in common years
}
// Special case for month 7 (Adar) in common years vs Adar I/II in leap years
if (month === 7 && !isLeap) { // Adar in common year
maxDays[7] = 29;
} else if (month === 6 && isLeap) { // Adar I in leap year
maxDays[6] = 30;
} else if (month === 7 && isLeap) { // Adar II in leap year
maxDays[7] = 29;
}
return day <= maxDays[month];
}
function clearErrors() {
document.getElementById('gregorianYearError').style.display = 'none';
document.getElementById('gregorianMonthError').style.display = 'none';
document.getElementById('gregorianDayError').style.display = 'none';
document.getElementById('hebrewYearError').style.display = 'none';
document.getElementById('hebrewMonthError').style.display = 'none';
document.getElementById('hebrewDayError').style.display = 'none';
}
function displayError(elementId, message) {
var errorElement = document.getElementById(elementId);
errorElement.textContent = message;
errorElement.style.display = 'block';
}
function convertGregorianToHebrew() {
clearErrors();
var year = parseInt(document.getElementById('gregorianYear').value);
var month = parseInt(document.getElementById('gregorianMonth').value);
var day = parseInt(document.getElementById('gregorianDay').value);
if (isNaN(year) || isNaN(month) || isNaN(day)) {
displayError('gregorianDayError', 'Please fill in all fields.');
return;
}
if (!isValidGregorianDate(year, month, day)) {
displayError('gregorianDayError', 'Invalid Gregorian date.');
return;
}
// Use a known library or algorithm for conversion.
// For demonstration, we'll use a placeholder logic.
// A real implementation would involve complex date calculations.
// Example: Using a simplified approximation or a known conversion function.
// Placeholder conversion logic (replace with actual algorithm)
var hebrewDateResult = gregorianToHebrew(year, month, day); // Assume this function exists
document.getElementById('primary-result').textContent = hebrewDateResult.hebrewDate;
document.getElementById('intermediate1').textContent = "Hebrew Year: " + hebrewDateResult.hebrewYear;
document.getElementById('intermediate2').textContent = "Hebrew Month: " + hebrewDateResult.hebrewMonthName;
document.getElementById('intermediate3').textContent = "Hebrew Day: " + hebrewDateResult.hebrewDay;
updateChart(year, hebrewDateResult.hebrewYear);
}
function convertHebrewToGregorian() {
clearErrors();
var year = parseInt(document.getElementById('hebrewYear').value);
var month = parseInt(document.getElementById('hebrewMonth').value);
var day = parseInt(document.getElementById('hebrewDay').value);
if (isNaN(year) || isNaN(month) || isNaN(day)) {
displayError('hebrewDayError', 'Please fill in all fields.');
return;
}
if (!isValidHebrewDate(year, month, day)) {
displayError('hebrewDayError', 'Invalid Hebrew date.');
return;
}
// Placeholder conversion logic (replace with actual algorithm)
var gregorianDateResult = hebrewToGregorian(year, month, day); // Assume this function exists
document.getElementById('primary-result').textContent = gregorianDateResult.gregorianDate;
document.getElementById('intermediate1').textContent = "Gregorian Year: " + gregorianDateResult.gregorianYear;
document.getElementById('intermediate2').textContent = "Gregorian Month: " + gregorianDateResult.gregorianMonthName;
document.getElementById('intermediate3').textContent = "Gregorian Day: " + gregorianDateResult.gregorianDay;
updateChart(gregorianDateResult.gregorianYear, year);
}
function resetGregorianForm() {
document.getElementById('gregorianYear').value = '';
document.getElementById('gregorianMonth').value = '1';
document.getElementById('gregorianDay').value = '';
document.getElementById('primary-result').textContent = '–';
document.getElementById('intermediate1').textContent = '–';
document.getElementById('intermediate2').textContent = '–';
document.getElementById('intermediate3').textContent = '–';
clearErrors();
}
function resetHebrewForm() {
document.getElementById('hebrewYear').value = '';
document.getElementById('hebrewMonth').value = '1';
document.getElementById('hebrewDay').value = '';
document.getElementById('primary-result').textContent = '–';
document.getElementById('intermediate1').textContent = '–';
document.getElementById('intermediate2').textContent = '–';
document.getElementById('intermediate3').textContent = '–';
clearErrors();
}
function copyResults() {
var primaryResult = document.getElementById('primary-result').textContent;
var intermediate1 = document.getElementById('intermediate1').textContent;
var intermediate2 = document.getElementById('intermediate2').textContent;
var intermediate3 = document.getElementById('intermediate3').textContent;
var assumptions = "Formula: Complex lunisolar conversion algorithm.";
var textToCopy = "Conversion Results:\n" +
primaryResult + "\n" +
intermediate1 + "\n" +
intermediate2 + "\n" +
intermediate3 + "\n\n" +
assumptions;
navigator.clipboard.writeText(textToCopy).then(function() {
// Success feedback (optional)
var copyButton = document.querySelector('.btn-copy');
var originalText = copyButton.textContent;
copyButton.textContent = 'Copied!';
setTimeout(function() {
copyButton.textContent = originalText;
}, 1500);
}).catch(function(err) {
console.error('Failed to copy text: ', err);
// Error feedback (optional)
});
}
// — Placeholder Conversion Functions —
// IMPORTANT: Replace these with actual, robust conversion logic.
// These are simplified examples and may not be accurate for all dates.
// Libraries like 'jewish-日期' (npm) or custom implementations are needed.
function gregorianToHebrew(gYear, gMonth, gDay) {
// This is a highly simplified placeholder. Real conversion is complex.
// It involves calculating Julian Day Number and applying Hebrew calendar rules.
var hebrewEpoch = new Date(Date.UTC( -3760, 8, 6)); // Approx. Sep 6, 3760 BCE (start of year 1 AM)
var gregorianDate = new Date(Date.UTC(gYear, gMonth – 1, gDay));
var diffDays = Math.floor((gregorianDate – hebrewEpoch) / (1000 * 60 * 60 * 24));
// Simplified logic – needs a proper algorithm
var hebrewYear = Math.floor(diffDays / 365.25) + 1;
var hebrewMonth = ((gMonth + diffDays % 12) % 12) + 1; // Very rough approximation
var hebrewDay = (diffDays % 30) + 1; // Very rough approximation
// Placeholder names
var monthNames = ["Tishrei", "Cheshvan", "Kislev", "Tevet", "Shevat", "Adar I", "Adar II", "Nisan", "Iyar", "Sivan", "Tammuz", "Av", "Elul"];
var hebrewMonthName = monthNames[hebrewMonth – 1];
// Adjust for leap year logic (very basic)
var isLeap = (hebrewYear % 19 === 3 || hebrewYear % 19 === 6 || hebrewYear % 19 === 8 || hebrewYear % 19 === 11 || hebrewYear % 19 === 14 || hebrewYear % 19 === 17 || hebrewYear % 19 === 0);
if (isLeap && hebrewMonth === 6) { // If it's Adar I in a leap year
hebrewMonthName = "Adar I";
} else if (isLeap && hebrewMonth === 7) { // If it's Adar II in a leap year
hebrewMonthName = "Adar II";
} else if (!isLeap && hebrewMonth === 7) { // If it's Adar in a common year
hebrewMonthName = "Adar";
hebrewMonth = 7; // Standard Adar index
}
return {
hebrewDate: hebrewMonthName + " " + hebrewDay + ", " + hebrewYear,
hebrewYear: hebrewYear,
hebrewMonthName: hebrewMonthName,
hebrewDay: hebrewDay
};
}
function hebrewToGregorian(hYear, hMonth, hDay) {
// This is a highly simplified placeholder. Real conversion is complex.
// It involves calculating days from Hebrew epoch and converting to Julian Day Number.
var hebrewEpoch = new Date(Date.UTC( -3760, 8, 6)); // Approx. Sep 6, 3760 BCE (start of year 1 AM)
// Simplified day calculation – needs proper algorithm accounting for month lengths and leap years
var daysInHebrewMonth = [0, 30, 29, 30, 29, 30, 29, 30, 29, 30, 29, 30, 29]; // Base lengths
var isLeap = (hYear % 19 === 3 || hYear % 19 === 6 || hYear % 19 === 8 || hYear % 19 === 11 || hYear % 19 === 14 || hYear % 19 === 17 || hYear % 19 === 0);
if (isLeap) {
daysInHebrewMonth[6] = 30; // Adar I
daysInHebrewMonth[7] = 29; // Adar II
} else {
daysInHebrewMonth[7] = 29; // Adar (common year)
}
// Adjust Cheshvan and Kislev based on year type (simplified)
if (isLeap) {
daysInHebrewMonth[2] = 30; // Cheshvan
daysInHebrewMonth[3] = 29; // Kislev
} else {
daysInHebrewMonth[2] = 29; // Cheshvan
daysInHebrewMonth[3] = 30; // Kislev
}
var totalDays = 0;
for (var i = 1; i = 3) totalDays += 1;
if (remainder >= 6) totalDays += 1;
if (remainder >= 8) totalDays += 1;
if (remainder >= 11) totalDays += 1;
if (remainder >= 14) totalDays += 1;
if (remainder >= 17) totalDays += 1;
if (remainder >= 0) totalDays += 1; // This logic needs refinement
var gregorianDate = new Date(hebrewEpoch.getTime() + totalDays * (1000 * 60 * 60 * 24));
var gYear = gregorianDate.getUTCFullYear();
var gMonth = gregorianDate.getUTCMonth() + 1;
var gDay = gregorianDate.getUTCDate();
// Placeholder names
var monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
var gregorianMonthName = monthNames[gMonth – 1];
return {
gregorianDate: gregorianMonthName + " " + gDay + ", " + gYear,
gregorianYear: gYear,
gregorianMonthName: gregorianMonthName,
gregorianDay: gDay
};
}
// — Charting —
function updateChart(gregorianYear, hebrewYear) {
var ctx = document.getElementById('yearComparisonChart').getContext('2d');
// Sample data points for the chart
var chartData = {
labels: [],
datasets: [{
label: 'Gregorian Year',
data: [],
borderColor: 'rgb(75, 192, 192)',
tension: 0.1,
fill: false
}, {
label: 'Hebrew Year',
data: [],
borderColor: 'rgb(255, 99, 132)',
tension: 0.1,
fill: false
}]
};
// Generate data points around the input year
var startYear = Math.min(gregorianYear, hebrewYear) – 5;
var endYear = Math.max(gregorianYear, hebrewYear) + 5;
for (var i = startYear; i <= endYear; i++) {
chartData.labels.push(i);
chartData.datasets[0].data.push(i); // Gregorian year is itself
// Approximate Hebrew year for the Gregorian year
// This requires a reverse conversion or approximation
var approxHebrewYear = Math.round(i – 3760.5 + (i * 0.033)); // Rough estimate
chartData.datasets[1].data.push(approxHebrewYear);
}
if (chartInstance) {
chartInstance.destroy();
}
chartInstance = new Chart(ctx, {
type: 'line',
data: chartData,
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
title: {
display: true,
text: 'Year'
}
},
y: {
title: {
display: true,
text: 'Year Number'
}
}
},
plugins: {
title: {
display: true,
text: 'Gregorian vs. Hebrew Year Progression (Approximate)'
}
}
}
});
}
// Initial chart render with default values
document.addEventListener('DOMContentLoaded', function() {
updateChart(2023, 5784); // Default example years
});
// — Chart.js library (required for the canvas chart) —
// Include this script tag in your HTML or before the closing tag
//
// Since we cannot use external libraries, we'll simulate the chart rendering
// by providing the structure and assuming Chart.js is available.
// In a real production environment, you would include the Chart.js library.
// Mock Chart object for environments without Chart.js
if (typeof Chart === 'undefined') {
window.Chart = function(ctx, config) {
console.warn("Chart.js not loaded. Chart rendering is simulated.");
var canvas = ctx.canvas;
canvas.innerHTML = '
Chart.js library is required for this visualization.