Set a fake date in your browser globally using Tampermonkey with UI controls
// ==UserScript==
// @name Fake Date with Controls
// @namespace fake-date-script
// @version 1.3
// @description Set a fake date in your browser globally using Tampermonkey with UI controls
// @match http://*/*
// @match https://*/*
// @grant none
// @license MIT
// @run-at document-start
// ==/UserScript==
(function() {
'use strict';
// Check if we should use real time
const useRealTime = localStorage.getItem('fakeDate_useRealTime') === 'true';
// Use a stored date or the default one
const storedDate = localStorage.getItem('fakeDateValue') || '2025-04-01T00:00:00.000Z';
let fakeDateValue = storedDate;
let fakeDate = new Date(fakeDateValue);
let fakeTimestamp = fakeDate.getTime();
let baseTime = Date.now(); // Capture the real time when script loads
// If useRealTime is true, set timeDifference to 0
let timeDifference = useRealTime ? 0 : (fakeTimestamp - baseTime);
const OriginalDate = Date;
function FakeDate(...args) {
if (args.length === 0) {
// Return current fake date when no args provided
return new OriginalDate(OriginalDate.now() + timeDifference);
}
return new OriginalDate(...args);
}
// Ensure all static methods are properly copied
FakeDate.now = function() {
return OriginalDate.now() + timeDifference;
};
FakeDate.parse = OriginalDate.parse;
FakeDate.UTC = OriginalDate.UTC;
// Properly copy prototype chain
FakeDate.prototype = OriginalDate.prototype;
FakeDate.toString = function() { return OriginalDate.toString(); };
FakeDate[Symbol.species] = OriginalDate;
// Override Date
window.Date = FakeDate;
// Override performance.now() to align with fake date
if (window.performance && window.performance.now) {
const originalNow = window.performance.now.bind(window.performance);
const perfTimeOrigin = performance.timeOrigin || 0;
window.performance.now = function() {
return originalNow() + (timeDifference);
};
// Update timeOrigin if it exists
if ('timeOrigin' in window.performance) {
Object.defineProperty(window.performance, 'timeOrigin', {
get: function() {
return perfTimeOrigin + timeDifference;
}
});
}
}
// Add UI functions
function updateTimeDisplay() {
const displayElem = document.getElementById('fake-time-display');
if (displayElem) {
displayElem.textContent = `Current Time: ${new Date().toLocaleString()}`;
}
// Update status indicator
const statusElem = document.getElementById('time-status');
if (statusElem) {
if (useRealTime) {
statusElem.textContent = '(REAL TIME)';
statusElem.style.color = '#4CAF50';
} else {
statusElem.textContent = '(FAKE TIME)';
statusElem.style.color = '#f44336';
}
}
}
// Create control panel when DOM is ready
function createControlPanel() {
// Add styles
const styles = `
#fake-date-control {
position: fixed;
bottom: 10px;
right: 10px;
background: white;
border: 1px solid #ccc;
border-radius: 5px;
padding: 10px;
z-index: 9999;
box-shadow: 0 0 10px rgba(0,0,0,0.2);
font-family: Arial, sans-serif;
width: 280px;
}
#fake-date-control button {
margin-right: 5px;
margin-top: 5px;
padding: 5px 10px;
border-radius: 3px;
border: 1px solid #ccc;
background: #f0f0f0;
cursor: pointer;
}
#fake-date-control button:hover {
background: #e0e0e0;
}
#fake-time-display {
margin-bottom: 5px;
font-weight: bold;
}
#time-status {
margin-bottom: 10px;
font-weight: bold;
}
#refresh-page {
background-color: #4CAF50 !important;
color: white;
}
#reset-date {
background-color: #f44336 !important;
color: white;
}
`;
const styleElement = document.createElement('style');
styleElement.textContent = styles;
document.head.appendChild(styleElement);
// Create panel
const panel = document.createElement('div');
panel.id = 'fake-date-control';
panel.innerHTML = `
<div id="fake-time-display">Current Time: ${new Date().toLocaleString()}</div>
<div id="time-status">${useRealTime ? '(REAL TIME)' : '(FAKE TIME)'}</div>
<input type="datetime-local" id="fake-date-input">
<div>
<button id="set-date">Set Date</button>
<button id="reset-date">Reset to Real Time</button>
</div>
<div>
<button id="refresh-page">Refresh Page</button>
<button id="hide-panel">Hide Panel</button>
</div>
`;
document.body.appendChild(panel);
// Set initial input value
const now = new Date();
const year = now.getFullYear();
const month = String(now.getMonth() + 1).padStart(2, '0');
const day = String(now.getDate()).padStart(2, '0');
const hours = String(now.getHours()).padStart(2, '0');
const minutes = String(now.getMinutes()).padStart(2, '0');
document.getElementById('fake-date-input').value = `${year}-${month}-${day}T${hours}:${minutes}`;
// Add event listeners
document.getElementById('set-date').addEventListener('click', function() {
const dateInput = document.getElementById('fake-date-input').value;
if (dateInput) {
localStorage.setItem('fakeDateValue', new Date(dateInput).toISOString());
localStorage.setItem('fakeDate_useRealTime', 'false');
alert('Date set! Click Refresh to apply changes.');
}
});
document.getElementById('reset-date').addEventListener('click', function() {
localStorage.setItem('fakeDate_useRealTime', 'true');
alert('Reset to real time! Click Refresh to apply changes.');
});
document.getElementById('refresh-page').addEventListener('click', function() {
window.location.reload();
});
document.getElementById('hide-panel').addEventListener('click', function() {
panel.style.display = 'none';
// Create show button
const showButton = document.createElement('button');
showButton.textContent = useRealTime ? '🕒' : '🕒*';
showButton.style.position = 'fixed';
showButton.style.bottom = '10px';
showButton.style.right = '10px';
showButton.style.zIndex = '9999';
showButton.style.padding = '5px 10px';
showButton.style.borderRadius = '3px';
showButton.style.border = '1px solid #ccc';
showButton.style.background = useRealTime ? '#f0f0f0' : '#ffecec';
showButton.style.cursor = 'pointer';
showButton.addEventListener('click', function() {
panel.style.display = 'block';
showButton.remove();
});
document.body.appendChild(showButton);
});
// Update time display every second
setInterval(updateTimeDisplay, 1000);
}
// Create control panel once the DOM is loaded
if (document.readyState === 'loading') {
document.addEventListener('DOMContentLoaded', createControlPanel);
} else {
setTimeout(createControlPanel, 500);
}
console.log('Fake Date script loaded. Current fake date:', new Date().toISOString(), 'Using real time:', useRealTime);
})();