calculate end date from duration - php

Question

I have a duration drop down menu with options 'yearly/quarterly/monthly' and start date textbox with datepicker. There is another textbox end_date.
Based on the duration I need the end date when duration and start date is selected.
E.g.: Start date is 23-09-2015 and duration chosen is 3 months so, I need to display 23-12-2015.But I have no idea how to do that.

Answer 1

PHP (5.3+) has a neat class to help adding a duration to a date its called DateInterval. (it has many other nice interval features as well)
$date = new DateTime('2015-10-02');
$date->add(new DateInterval('P3M'));
echo $date->format('Y-m-d'); // 2016-01-02
In the example above i add 3 months to my date. You can do other more complex things like P4Y1M2D, which is 2 days, 1 month and 4 years....
See php doc for more information: DateInterval
For a tutorial go here: Add a duration or interval to a date

Answer 2

Try this. This is an example. I hope this will help.
<?php
$date = date("Y-m-d");
$date = strtotime(date("Y-m-d", strtotime($date)) . " +3 month");
echo date("Y-m-d",$date);
?>
If you need to add months and date do like this
$date = strtotime(date("Y-m-d", strtotime($date)) . " +3 month 2 day");

Answer 3

use
$date = date_create('2015-09-30');
date_add($date, date_interval_create_from_date_string('3 Months'));
echo date_format($date, 'Y-m-d');

Answer 4

Please check this
<link rel="stylesheet" href="//code.jquery.com/ui/1.11.4/themes/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<script>
$(document).ready(function(){
$("#start_date").removeClass('hasDatepicker').datepicker(
{
changeMonth: true,
changeYear: true,
dateFormat: 'yy-mm-dd',
onSelect: function(selectedDate)
{
var d = new Date( selectedDate );
if($('.date_range').val() == 'Yearly')
{
d.setFullYear( d.getFullYear( ) + 1 );
}
if($('.date_range').val() == 'Quarterly')
{
d.setMonth( d.getMonth( ) + 3 );
}
if($('.date_range').val() == 'Monthly')
{
d.setMonth( d.getMonth( ) + 1 );
}
year = d.getFullYear();
month = ("0" + (d.getMonth() + 1)).slice(-2);
date = ("0" + d.getDate()).slice(-2);
end_date = year +'-'+month+'-'+date;
$('#end_date').val(end_date);
}
});
});
</script>
<select name="date_range" class="date_range">
<option value="None">Please select a date range</option>
<option value="Yearly">Yearly</option>
<option value="Quarterly">Quarterly</option>
<option value="Monthly">Monthly</option>
</select>
<p>Start Date</p>
<input type="text" name="start_date" id="start_date" />
<p>End Date</p>
<input type="text" name="end_date" id="end_date" />