Forbid users from setting too large delays

admin/class-steempress_sp-admin.php

@@ -151,7 +151,7 @@ class Steempress_sp_Admin {
         $valid['seo'] = ((isset($input['seo']) && !empty($input['seo'])) && $input['seo'] == 'on') ? 'on' : "off";
         $valid['vote'] = ((isset($input['vote']) && !empty($input['vote'])) && $input['vote'] == 'on') ? 'on' : "off";
         $valid['append'] = ((isset($input['append']) && !empty($input['append'])) && $input['append'] == 'on') ? 'on' : "off";
-        $valid['delay'] = ((isset($input['delay']) && !empty($input['delay']) && is_numeric($input['delay']) && $input['delay'] >= 0)) ?  htmlspecialchars($input['delay'], ENT_QUOTES) : "0";
+        $valid['delay'] = ((isset($input['delay']) && !empty($input['delay']) && is_numeric($input['delay']) && $input['delay'] >= 0 && $input['delay'] <= 87600)) ?  htmlspecialchars($input['delay'], ENT_QUOTES) : "0";
         $valid['featured'] = ((isset($input['featured']) && !empty($input['featured'])) && $input['featured'] == 'on') ? 'on' : "off";
         $valid['footer'] = (isset($input['footer']) && !empty($input['footer'])) ? $input['footer'] : "<br /><center><hr/><em>Posted from my blog with <a href='https://wordpress.org/plugins/steempress/'>SteemPress</a> : [%original_link%] </em><hr/></center>";
         $valid['twoway'] = ((isset($input['twoway']) && !empty($input['twoway'])) && $input['twoway'] == 'on') ? 'on' : "off";

admin/partials/steempress_sp-admin-display.php

@@ -106,8 +106,8 @@
         <p> Default tags : <br> separate each tag by a space, 5 max <br> Will be used if you don't specify tags when publishing. </p>
         <input type="text" class="regular-text" id="<?php echo $this->plugin_name; ?>-tags" name="<?php echo $this->plugin_name; ?>[tags]" value="<?php echo htmlspecialchars(($options["tags"] == "" ? "steempress blog" : $options["tags"]), ENT_QUOTES); ?>"/>
         <br />
-        <p> Delay posts : Your posts will get published to steem x minutes after being published on your blog. A value of 0 posts your articles to steem as soon as you publish them.</p>
-        <input type="number" class="regular-text" id="<?php echo $this->plugin_name; ?>-delay" name="<?php echo $this->plugin_name; ?>[delay]" value="<?php echo htmlspecialchars(($options["delay"] == "" ? "0" : $options["delay"]), ENT_QUOTES); ?>"/>
+        <p> Delay posts : Your posts will get published to steem x minutes after being published on your blog. A value of 0 posts your articles to steem as soon as you publish them. maximum value is 87600, 2 months. </p>
+        <input type="number" max="87600" class="regular-text" id="<?php echo $this->plugin_name; ?>-delay" name="<?php echo $this->plugin_name; ?>[delay]" value="<?php echo htmlspecialchars(($options["delay"] == "" ? "0" : $options["delay"]), ENT_QUOTES); ?>"/>
         <br />
         <br />