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Tutorial

Timestamp 1970 1969

Timestamp is very important for the Business Suite and other accounting application. Years and months are commonly used to create the directories for data records.

The strtotime() function in PHP is used to parse a date and time string into a Unix timestamp, and if an empty string is passed as its argument, it returns false. When you use date("Ymd", strtotime("")), strtotime("") returns false, which is then interpreted as 0 when used in a date function.

The Unix timestamp 0 corresponds to January 1, 1970, 00:00:00 UTC. However, when you adjust for time zones (if your server or environment is set to a negative UTC offset, such as UTC-5 or similar), this timestamp could display as December 31, 1969.

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Functions used in this webpage:

PHP

PHP strtotime() Function
PHP date() Function
PHP echo() Function
ChatGPT

This totuorial using the company profile accounting month as example.

If clear the accounting month, the system will detect the month as 1969 or 1970. This will affect the creation of the data directory back dated to those years. More check condition needed to prevent this from happening.

Coding area:

<?php 	/* Set maximum execution time to 30 seconds*/
set_time_limit(30);
$profile_file = "profile_file.txt";
/* Change the accounting month */
$submit = $_POST["submit"];
$accmonth = trim($_POST["accmonth"]);
if ($submit == "Update")
{
/* echo "Next accounting month = ".$accmonth."<br>"; */
/* Read the file into an array */
$fileLines = file($profile_file, FILE_IGNORE_NEW_LINES);
/* Check if the line number is valid */
$lineNumber = 5;
if ($lineNumber < 0 || $lineNumber >= count($fileLines))
{
throw new Exception("Invalid line number");
}
/* Modify the specific line */
$fileLines[$lineNumber] = $accmonth;
/* Write the array back to the file */
file_put_contents($profile_file, implode(PHP_EOL, $fileLines));
/* echo "End of change acc month "."<br>"; */
}
/* Read profile file line*/
$fileLines = file($profile_file, FILE_IGNORE_NEW_LINES);
/* Check if the line number is valid */
$lineNumber = 5;
if ($lineNumber < 0 || $lineNumber >= count($fileLines))
{
throw new Exception("Invalid line number");
}
/* read the line 2 the photo url line */
$line_data = $fileLines[$lineNumber];
/* Display received data for checking*/
echo "line = ".$line_data;
echo "<br>";
if ($accmonth == "")
{
$accmonth = $line_data;	
}

?>
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
<style>					.form-popup {			display: none;			position: fixed;			left: 50%;			top: 50%;			transform: translate(-50%, -50%);			border: 3px solid #f1f1f1;			z-index: 9;			background-color: white;			padding: 20px;			box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2);			}			.form-container {			width: 100%;			padding: 10px;			}			.form-container input[type=text], .form-container input[type=email] {			width: 100%;			padding: 15px;			margin: 5px 0 22px 0;			border: none;			background: #f1f1f1;			}			.form-container input[type=text]:focus, .form-container input[type=email]:focus {			background-color: #ddd;			outline: none;			}			.form-container .btn {			background-color: #4CAF50;			color: white;			padding: 16px 20px;			border: none;			cursor: pointer;			width: 100%;			margin-bottom:10px;			opacity: 0.8;			}			.form-container .cancel {			background-color: red;			}			.form-container .btn:hover, .open-button:hover {			opacity: 1;			}		</style>	</head>	<body>		<div id="contentarea">			<p><br><b>Company Profile line data</b><br></p>			<table border="0" width="100%">  				<tbody>					<tr>																		<td align="left" width="500">							<h3>								<b>																		<font color="#ff6600">										Fiscal Months:<br>										<u>											<?php												echo date('M',strtotime('- 1 year', strtotime($accmonth)))." to ".date('M',strtotime('- 1 month', strtotime($accmonth)))."<br>";											?>										</u>									</font>								</b>      							</h3>						</td>					</tr>					<tr>												<td align="left">																												<button id="openFormBtn1">Edit fiscal year</button>														<div id="popupForm1" class="form-popup">								<form  name="orderForm" action="w3diy_timestamp.php" method="post" onsubmit="return checkforblank()" class="form-container">									<p>Month 1 of the next fiscal year.</p>									<p>(This function should be removed when the company profile is in place.)</p>									<p><input name="accmonth" value="<?php echo $accmonth; ?>" size="30" type="month"></p>														<input type="submit" value="Update" name="submit">								</form>								<button id="closeFormBtn1">Close</button>							</div>							<script>								document.getElementById("openFormBtn1").addEventListener("click", function() {									document.getElementById("popupForm1").style.display = "block";								});								document.getElementById("closeFormBtn1").addEventListener("click", function() {									document.getElementById("popupForm1").style.display = "none";								});															</script>										<br><br>						</td>					</tr>								<tr>										<td align="left">																																				<div id="popupForm3" class="form-popup">														<?php echo nl2br($Message); ?>															<button id="closeFormBtn3">Close</button>						</div>						<script>							document.getElementById("closeFormBtn3").addEventListener("click", function() {								document.getElementById("popupForm3").style.display = "none";								document.getElementById("popupForm1").style.display = "block";							});																				</script>													<br><br>					</td>				</tr>																		</tbody>		</table>		<table border="0" width="100%">			<tbody>					<tr>					<td align="left">						<h2><b>
							<?php 								echo "Line ".$lineNumber.":<br>";								echo $line_data."<br>";								echo "date = ".date("Y", strtotime($accmonth));							?>						</b></h2>
<a href="https://dotdesign.com.sg/acc.php?directory=public&user=ho">Business suite</a>				</td>				</tr>			</tbody>		</table>	</div></body></html>