Time Calculator Hourly

body {
font-family: ‘Segoe UI’, Tahoma, Geneva, Verdana, sans-serif;
background-color: #f8f9fa;
color: #333;
line-height: 1.6;
margin: 0;
padding: 20px;
display: flex;
justify-content: center;
align-items: flex-start;
min-height: 100vh;
}
.loan-calc-container {
background-color: #ffffff;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 74, 153, 0.1);
padding: 30px;
width: 100%;
max-width: 700px;
border: 1px solid #e0e0e0;
}
h1 {
color: #004a99;
text-align: center;
margin-bottom: 25px;
font-size: 2.2em;
border-bottom: 2px solid #004a99;
padding-bottom: 10px;
}
.description {
font-size: 0.95em;
color: #555;
text-align: center;
margin-bottom: 30px;
}
.calculator-section {
margin-bottom: 30px;
padding: 20px;
background-color: #e9ecef;
border-radius: 6px;
border: 1px solid #dee2e6;
}
.calculator-section h2 {
color: #004a99;
margin-top: 0;
margin-bottom: 15px;
font-size: 1.5em;
}
.input-group {
margin-bottom: 15px;
display: flex;
flex-direction: column;
align-items: flex-start;
}
.input-group label {
font-weight: bold;
margin-bottom: 8px;
color: #004a99;
font-size: 1.1em;
}
.input-group input[type=”number”],
.input-group select {
width: 100%;
padding: 10px 12px;
border: 1px solid #ced4da;
border-radius: 4px;
box-sizing: border-box;
font-size: 1em;
transition: border-color 0.3s ease;
}
.input-group input[type=”number”]:focus,
.input-group select:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}
button {
background-color: #004a99;
color: white;
border: none;
padding: 12px 25px;
border-radius: 5px;
font-size: 1.1em;
cursor: pointer;
transition: background-color 0.3s ease, transform 0.2s ease;
display: block;
width: 100%;
margin-top: 10px;
}
button:hover {
background-color: #003d82;
transform: translateY(-2px);
}
#result {
margin-top: 25px;
padding: 20px;
background-color: #28a745;
color: white;
text-align: center;
border-radius: 6px;
font-size: 1.8em;
font-weight: bold;
box-shadow: 0 2px 10px rgba(40, 167, 69, 0.3);
}
#result span {
font-size: 1em;
}
.article-section {
margin-top: 40px;
padding: 25px;
background-color: #f8f9fa;
border-radius: 8px;
border: 1px solid #e0e0e0;
}
.article-section h3 {
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font-size: 1.8em;
margin-top: 0;
margin-bottom: 15px;
border-bottom: 1px solid #004a99;
padding-bottom: 8px;
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.article-section p {
margin-bottom: 15px;
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.article-section strong {
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.article-section ul {
list-style-type: disc;
margin-left: 20px;
color: #555;
}
.article-section li {
margin-bottom: 8px;
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@media (max-width: 600px) {
.loan-calc-container {
padding: 20px;
}
h1 {
font-size: 1.8em;
}
#result {
font-size: 1.5em;
}
button {
font-size: 1em;
padding: 10px 20px;
}
.article-section h3 {
font-size: 1.5em;
}
}

Calculate the total duration between two times, expressed in hours and minutes.

Input Times

Understanding Time Duration Calculation

This calculator helps determine the precise duration between two points in time, taking into account both the hours and minutes of the day, as well as the difference in calendar dates. It’s a fundamental calculation used in many scenarios, from project management and employee time tracking to scheduling and logistics.

How it Works (The Math Behind It)

The calculation involves converting both the start and end times into a common unit, typically minutes from a reference point (like the beginning of a day or a specific date), and then finding the difference. Here’s a breakdown:

1. Convert to Minutes:
   Each time is converted into total minutes.
   • For a given time (H hours, M minutes), the total minutes are calculated as: (H * 60) + M
2. Account for Dates:
   If the end date is different from the start date, we need to add the duration of the full days in between.
   • Calculate the number of full days between startDate and endDate. A day is 24 hours, which is 24 * 60 = 1440 minutes.
   • Total minutes for a date = (Number of full days between dates * 1440)
3. Combine and Subtract:
   The total minutes for the start and end times are calculated:
   • Total Start Minutes = (Start Date minutes) + (Start Hour * 60) + Start Minute
   • Total End Minutes = (End Date minutes) + (End Hour * 60) + End Minute

   The duration in minutes is then: Total End Minutes - Total Start Minutes.

4. Convert Back to Hours and Minutes:
   The final duration in minutes is converted back into a more readable format:
   • Duration Hours = floor(Total Duration Minutes / 60)
   • Duration Minutes = Total Duration Minutes % 60

   If the start time is later than the end time on the same day and no specific end date is provided that implies crossing midnight, the calculator might infer a duration that spans across midnight or consider the end time to be on the next day if dates are different. This calculator assumes the end time is chronologically after the start time, considering the dates.

Use Cases:

• Employee Time Tracking: Calculating total work hours for payroll.
• Project Management: Estimating or logging time spent on tasks.
• Billing Services: Charging clients based on time spent.
• Logistics and Transportation: Determining travel or delivery times.
• Event Planning: Scheduling and calculating event durations.
• Personal Time Management: Understanding how time is spent daily.

This tool provides a reliable way to perform these calculations accurately and efficiently.

function calculateTimeDifference() {
var startHour = parseInt(document.getElementById(“startHour”).value);
var startMinute = parseInt(document.getElementById(“startMinute”).value);
var endHour = parseInt(document.getElementById(“endHour”).value);
var endMinute = parseInt(document.getElementById(“endMinute”).value);
var startDateInput = document.getElementById(“startDate”).value;
var endDateInput = document.getElementById(“endDate”).value;

var resultDiv = document.getElementById(“result”);
resultDiv.querySelector(‘span’).textContent = ”; // Clear previous result

// Input validation
if (isNaN(startHour) || isNaN(startMinute) || isNaN(endHour) || isNaN(endMinute) ||
startHour 23 || startMinute 59 ||
endHour 23 || endMinute 59) {
resultDiv.querySelector(‘span’).textContent = “Please enter valid hours (0-23) and minutes (0-59).”;
return;
}

var startMoment = new Date();
var endMoment = new Date();

// Set initial date values, default to today if empty
var today = new Date();
var startDateObj = startDateInput ? new Date(startDateInput) : today;
var endDateObj = endDateInput ? new Date(endDateInput) : today;

// Ensure dates are valid, default to today if invalid input
if (isNaN(startDateObj.getTime())) {
startDateObj = today;
document.getElementById(“startDate”).value = today.toISOString().split(‘T’)[0];
}
if (isNaN(endDateObj.getTime())) {
endDateObj = today;
document.getElementById(“endDate”).value = today.toISOString().split(‘T’)[0];
}

// Set times for start and end moments
startMoment.setFullYear(startDateObj.getFullYear(), startDateObj.getMonth(), startDateObj.getDate());
startMoment.setHours(startHour, startMinute, 0, 0);

endMoment.setFullYear(endDateObj.getFullYear(), endDateObj.getMonth(), endDateObj.getDate());
endMoment.setHours(endHour, endMinute, 0, 0);

// If end time is chronologically before start time on the same day, and dates are the same,
// assume end time is on the next day. This is a common interpretation for time difference.
// Alternatively, if end date is explicitly later, that takes precedence.
if (startMoment.getTime() > endMoment.getTime() && startDateObj.toDateString() === endDateObj.toDateString()) {
// Add one day to the endMoment
endMoment.setDate(endMoment.getDate() + 1);
} else if (startMoment.getTime() > endMoment.getTime() && startDateObj.getTime() !== endDateObj.getTime()) {
// This case handles situations where a user might input an earlier start time/date
// and a later end time/date that still results in start > end, which is illogical for duration.
// We rely on the fact that if dates are different, the later date is assumed to be the end date chronologically.
// However, if the user inputs eg. Start: 10 AM Jan 2, End: 9 AM Jan 1, this logic will error.
// For simplicity, we will prioritize the date difference and then time.
// If the end date is chronologically BEFORE the start date, this is an invalid input for duration.
if (endDateObj.getTime() < startDateObj.getTime()) {
resultDiv.querySelector('span').textContent = "End date cannot be before start date.";
return;
}
}

var differenceInMilliseconds = endMoment.getTime() – startMoment.getTime();

if (differenceInMilliseconds < 0) {
// This should ideally not happen with the logic above, but as a safeguard.
resultDiv.querySelector('span').textContent = "Invalid time or date input resulting in negative duration.";
return;
}

var totalMinutes = Math.floor(differenceInMilliseconds / (1000 * 60));
var hours = Math.floor(totalMinutes / 60);
var minutes = totalMinutes % 60;

resultDiv.querySelector('span').textContent = hours + " hours and " + minutes + " minutes";
}