Exemplo de calendario

Calendario.php

<?php

/**
 * Class Calendario
 */
class Calendario
{

    /**
     * @var int
     */
    public $dia;

    /**
     * @var
     */
    public $mes;

    /**
     * @var
     */
    public $ano;

    /**
     * @var
     */
    public $tstamp;

    /**
     * @var
     */
    public $dtmanip;

    /**
     * @var
     */
    public $dsprimdia;

    /**
     * @var bool
     */
    public $linhafechada;

    /**
     * @var
     */
    public $agendas;

    /**
     * @var
     */
    public $eventos;
    /**
     * @var array
     */
    public $nome = [];

    /**
     * @var array
     */
    public $cor = [];

    /**
     * Calendario constructor.
     * @param $pmes
     * @param $pano
     */
    public function __construct($pmes, $pano)
    {
        $this->linhafechada = true;
        $this->dia = 1;
        $this->mes = $pmes;
        $this->ano = $pano;
        $this->calcula_tstamp();
        $this->data_manipulavel();
        $this->primeiro_dia_mes();
    }

    /**
     *
     */
    public function calcula_tstamp()
    {
        $this->tstamp = mktime(0, 0, 0, $this->mes, $this->dia, $this->ano);
    }

    /**
     *
     */
    public function data_manipulavel()
    {
        $this->dtmanip = getdate($this->tstamp);
    }

    /**
     *
     */
    public function primeiro_dia_mes()
    {
        $this->dsprimdia = $this->dtmanip["wday"];
    }

    /**
     *
     */
    public function proximo_dia()
    {
        $this->dia++;
        $this->calcula_tstamp();
    }

    /**
     * @return string
     */
    public function exibe_calendario()
    {
        $html = "";
        $larg = 100.0 / 7.0;
        $html .= "<table id='tblLista' class='table table-bordered table-striped table-condensed table-hover' border='1' width='100%' cellpadding='0' cellspacing='0' align='center' bordercolor='#333333'>";
        $html .= "<tr class='bold' style='height: 50px; vertical-align: middle'>\n";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Dom</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Seg</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Ter</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Qua</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Qui</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Sex</td>";
        $html .= "<td class='text-center info' align='center' width='" . $larg . "%'>Sab</td>";
        $html .= "</tr>";

        $ccol = 0;
        $casa = 0;
        while (checkdate($this->mes, $this->dia, $this->ano)) {
            $data = date('Y-m-d', strtotime("{$this->ano}-{$this->mes}-{$this->dia}"));
            if ($this->linhafechada) {
                $html .= "<tr>\n";
                $this->linhafechada = false;
            }
            if ($casa < $this->dsprimdia) {
                $html .= "<td style='height: 95px; vertical-align: middle'> </td>";
            } else {
                $background = subDateCompare($data, "=") ? "background: #fdf9e7" : null;
                $html .= "<td style=\"height: 95px;$background\" align='center'>";
                $html .= $this->dia . "<br />";
                $html .= $this->getEventoDia($data);
                $html .= "</td>";
                $this->proximo_dia();
            }
            $ccol++;
            $ccol = $ccol % 7;
            $casa++;
            if (($casa % 7) == 0) {
                $html .= "</tr>";
                $this->linhafecha = true;
            }
        }
        while ($ccol != 0) {
            $ccol++;
            $ccol = $ccol % 7;
            $html .= "<td style='height: 95px; vertical-align: middle'> </td>";
        }
        $html .= "</tr>";

        $html .= "</table>";
        return $html;
    }

    /**
     * @param $data
     * @return null|string
     */
    public function getEventoDia($data)
    {
        $eventos = null;
        $html = null;
        $atrazos = 0;
        foreach ((array)$this->eventos[$data] as $k => $evento) {
            $agendamentos = 0;
            $livres = 0;

            if (is_array($evento['agendados'])) {
                array_walk($evento['agendados'], function ($v) use (&$agendamentos, &$atrazos) {
                    $agendamentos += sizeof($v);
                    foreach ((array)$v as $item) {
                        if (intval($item['status']) == 0 && subDateCompare($item['data'], "<")) {
                            $atrazos++;
                        }
                    }
                });
            }

            if (is_array($evento['horarios'])) {
                array_walk($evento['horarios'], function ($v) use (&$livres) {
                    if (is_array($v)) {
                        $livres += sizeof($v);
                    }
                });
            }

            $html .= "<a href='#' class='ev-cal' style='text-decoration: none' data-dt='" . toUserDate($data) . "' data-id='" . $k . "'>";
            $html .= "<div class='text-center' style='padding: 1px; vertical-align: middle'>";
            $html .= "<span class='label label-sm' style='background:" . $evento['cor'] . "'>{$this->nome[$k]}: {$agendamentos} de {$livres}</span> <br />";
            $html .= "</div>";
            $html .= "</a>";
        }

        if ($atrazos > 0) {
            $html .= "<a href='#' class='ev-cal' style='text-decoration: none' data-dt='" . toUserDate($data) . "'>";
            $html .= "<div class='text-center ev-cal' style='padding: 1px; vertical-align: middle'>";
            $html .= "<span class='label label-sm' style='background:red'>ATRASOS: {$atrazos}</span> <br />";
            $html .= "</div>";
            $html .= "</a>";
        }

        return $html;
    }
}