How to show calendar month's previous days? - php

Question

I'm trying to make a calendar that shows this month, and then fills in the remaining days on the end rows with the dates from the next and previous months.
I managed to make it show next months dates and the thing is the issue is that I need it to show previous months dates as well.
If someone manages to figure out the issues please add what the problem was as well how you managed to fix it, to help me in the future.
I will add a image of the calendar as well.
The script:
<table cellspacing="0" cellpadding="0" border="0" width="100%" class="view-calendar">
<tr>
<td valign="top" width="14.2857%">Mondag</td>
<td valign="top" width="14.2857%">Tuesday</td>
<td valign="top" width="14.2857%">Wednesday</td>
<td valign="top" width="14.2857%">Thursday</td>
<td valign="top" width="14.2857%">Friday</td>
<td valign="top" width="14.2857%">Saturday</td>
<td valign="top" width="14.2857%">Sunday</td>
</tr>
<?php
// Get current month dates
$days_count = date('t');
$current_day = date('d');
$week_day_first = date('N', mktime(0, 0, 0, date('m'), 1, date('Y')));
// Get previous month dates
// Get next month dates
$next_start = strtotime(date("Y-m-00", strtotime("+1 month")));
$next_dates = array();
for ($w = 1 - $week_day_first + 1; $w <= $days_count; $w = $w + 7){
echo '<tr>';
$counter = 0;
for ($d = $w; $d <= $w + 6; $d++){
if($d < 10){
$current_date = date("Y").date("m").'0'.$d;
}else{
$current_date = date("Y").date("m").$d;
}
echo '<td valign="top" width="14.2857%"'.(($d > 0 ? ($d > $days_count ? ' class="disabled"' : '') : ' class="disabled"')).(($counter > 4 ? ' class="week-day"' : '')).'>';
if($d > 0){
if($d > $days_count){
for($in = 1; $in <= 1; $in++){
echo array_push($next_dates, date('j', strtotime("+ $in day", $next_start)));
}
}else if($current_day == $d){
echo '<div class="current-day"><span class="given-date">'.$d.'</span></div>';
}else{
echo '<span class="given-date">'.$d.'</span>';
}
}else{
//Here comes previous dates
}
echo '</td>';
$counter++;
}
echo '</tr>';
}
?>
</table>

Answer 1

When you calculated $week_day_first, you can save your time calculated from the first day of the month into a variable.
$time_first_day_of_month = mktime(0, 0, 0, date('m'), 1, date('Y'));
Then you can reuse that later to calculate the offset of days before the first of the month.
date('d', strtotime("$offset day",$time_first_day_of_month))
Putting it all together:
<table cellspacing="0" cellpadding="0" border="0" width="100%" class="view-calendar">
<tr>
<td valign="top" width="14.2857%">Mondag</td>
<td valign="top" width="14.2857%">Tuesday</td>
<td valign="top" width="14.2857%">Wednesday</td>
<td valign="top" width="14.2857%">Thursday</td>
<td valign="top" width="14.2857%">Friday</td>
<td valign="top" width="14.2857%">Saturday</td>
<td valign="top" width="14.2857%">Sunday</td>
</tr>
<?php
// Get current month dates
$days_count = date('t');
$current_day = date('d');
// save time of first day for later use
$time_first_day_of_month = mktime(0, 0, 0, date('m'), 1, date('Y'));
$week_day_first = date('N', $time_first_day_of_month);
// Get next month dates
$next_start = strtotime(date("Y-m-00", strtotime("+1 month")));
$next_dates = array();
for ($w = 1 - $week_day_first + 1; $w <= $days_count; $w = $w + 7){
echo '<tr>';
$counter = 0;
for ($d = $w; $d <= $w + 6; $d++){
if($d < 10){
$current_date = date("Y").date("m").'0'.$d;
}else{
$current_date = date("Y").date("m").$d;
}
echo '<td valign="top" width="14.2857%"'.(($d > 0 ? ($d > $days_count ? ' class="disabled"' : '') : ' class="disabled"')).(($counter > 4 ? ' class="week-day"' : '')).'>';
if($d > 0){
// next month's dates
if($d > $days_count){
for($in = 1; $in <= 1; $in++){
echo array_push($next_dates, date('j', strtotime("+ $in day", $next_start)));
}
}
// today
else if($current_day == $d){
echo '<div class="current-day"><span class="given-date">'.$d.'</span></div>';
}
// this month's dates
else{
echo '<span class="given-date">'.$d.'</span>';
}
}
// last month's dates
else{
//Here comes previous dates
$offset = $d - 1;
echo '<span class="given-date">'.date('d', strtotime("$offset day",$time_first_day_of_month)).'</span>';
}
echo '</td>';
$counter++;
}
echo '</tr>';
}
?>
</table>
Results in this output:
<table cellspacing="0" cellpadding="0" border="0" width="100%" class="view-calendar">
<tr>
<td valign="top" width="14.2857%">Mondag</td>
<td valign="top" width="14.2857%">Tuesday</td>
<td valign="top" width="14.2857%">Wednesday</td>
<td valign="top" width="14.2857%">Thursday</td>
<td valign="top" width="14.2857%">Friday</td>
<td valign="top" width="14.2857%">Saturday</td>
<td valign="top" width="14.2857%">Sunday</td>
</tr>
<tr><td valign="top" width="14.2857%" class="disabled"><span class="given-date">30</span></td><td valign="top" width="14.2857%" class="disabled"><span class="given-date">31</span></td><td valign="top" width="14.2857%"><span class="given-date">1</span></td><td valign="top" width="14.2857%"><span class="given-date">2</span></td><td valign="top" width="14.2857%"><span class="given-date">3</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">4</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">5</span></td></tr><tr><td valign="top" width="14.2857%"><span class="given-date">6</span></td><td valign="top" width="14.2857%"><span class="given-date">7</span></td><td valign="top" width="14.2857%"><span class="given-date">8</span></td><td valign="top" width="14.2857%"><span class="given-date">9</span></td><td valign="top" width="14.2857%"><span class="given-date">10</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">11</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">12</span></td></tr><tr><td valign="top" width="14.2857%"><span class="given-date">13</span></td><td valign="top" width="14.2857%"><span class="given-date">14</span></td><td valign="top" width="14.2857%"><span class="given-date">15</span></td><td valign="top" width="14.2857%"><span class="given-date">16</span></td><td valign="top" width="14.2857%"><div class="current-day"><span class="given-date">17</span></div></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">18</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">19</span></td></tr><tr><td valign="top" width="14.2857%"><span class="given-date">20</span></td><td valign="top" width="14.2857%"><span class="given-date">21</span></td><td valign="top" width="14.2857%"><span class="given-date">22</span></td><td valign="top" width="14.2857%"><span class="given-date">23</span></td><td valign="top" width="14.2857%"><span class="given-date">24</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">25</span></td><td valign="top" width="14.2857%" class="week-day"><span class="given-date">26</span></td></tr><tr><td valign="top" width="14.2857%"><span class="given-date">27</span></td><td valign="top" width="14.2857%"><span class="given-date">28</span></td><td valign="top" width="14.2857%"><span class="given-date">29</span></td><td valign="top" width="14.2857%"><span class="given-date">30</span></td><td valign="top" width="14.2857%" class="disabled">1</td><td valign="top" width="14.2857%" class="disabled" class="week-day">2</td><td valign="top" width="14.2857%" class="disabled" class="week-day">3</td></tr></table>

Answer 2

Here is code using the DateTime class, which makes it quite readable:
$today = new DateTime('today'); // only change this line to test other months
$this_month = $today->format('M');
$date = clone $today;
$date->modify('first day of this month')->modify('+1 day')->modify('last Monday');
do {
echo '<tr>';
for ($weekday = 0; $weekday < 7; $weekday++){
$out = str_replace($this_month, '', $date->format('M'));
$content = "<span class='given-date'>$out {$date->format('d')}</span>";
if ($today == $date) $content = "<div class='current-day'>$content</div>";
$class = ($out ? 'disabled ' : '') . ($weekday > 4 ? 'week-day' : '');
echo "<td valign='top' width='14.2857%' class='$class'>$content</td>";
$date->modify('+1 day');
}
echo '</tr>';
} while ($date->format('M') == $this_month);

Answer 3

Although this is quite old now I found Jeff's solution very useful. I refactored it a little and put it in this Gist, I hope someone finds it useful. Part of it is here:
/**
* Return part of an HTML table containing all the days
* in the current month, plus padd it with next and
* previous months days if needed to fill out the grid
*
*
* #param date $date date object containing month to display
*
* #return string
*/
function get_calendar_days_in_month_html($date) {
$date_format = "Y-m-d";
$days_count = $date->format('t'); //Get number of days in this month
$weeks_count = ceil($days_count / 7); //How many weeks in this month?
$total_cells = $weeks_count * 7;
//clone is used or we literally are modifying the $date variable
$first_date_of_month = clone $date->modify('first day of this month');
$first_day_of_month = $first_date_of_month->format("N"); //returns 1-7 EG Mon-Fri
$first_date_of_grid = $first_date_of_month ->modify('-' . $first_day_of_month . ' days');
$todays_date = new DateTime();
$todays_date_str = $todays_date->format($date_format);
$selected_date_str = $date->format($date_format);
$day_of_week = 1; //FIXME: allow starting with Sunday or whatever
$ht = '<tr>';
for ($cell=1; $cell <= $total_cells ; $cell++) {
$classes = []; //CSS classes
$current_date = $first_date_of_grid->modify("+1 day");
$current_date_str = $current_date->format($date_format);
if($current_date_str == $todays_date_str) $classes[] = "today";
if($selected_date_str == $todays_date_str) $classes[] = "selected-date";
/* if current date is not from this month (EG previous or next month) then give
it a special class, you might want to grey it out or whatever */
if($date->format("m") !== $current_date->format("m")) $classes[] = "grid-filler";
$ht .= '
<td date="' . $current_date_str . '" class="' . implode(" ", $classes) . '">' . $current_date->format("j") . '</td>';
$day_of_week ++;
if($day_of_week == 8) {
$ht .= '</tr>';
if($cell < $total_cells) $ht .= '<tr>';
$day_of_week = 1;
}
}
return $ht;
}