diff --git a/composer.json b/composer.json
index a970b15..18c8fb5 100644
--- a/composer.json
+++ b/composer.json
@@ -3,8 +3,8 @@
     "description": "A script to report on Redmine tickets that need attention.",
     "type": "project",
     "require": {
-        "kbsali/redmine-api": "^1.5",
-        "vlucas/phpdotenv": "^4.1"
+        "vlucas/phpdotenv": "^4.1",
+        "azuyalabs/yasumi": "^2.2"
     },
     "license": "GPL",
     "authors": [
diff --git a/composer.lock b/composer.lock
index 0de94b9..4c9c403 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,36 +4,39 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "9d1110731b1633c82d10df7e5b5077a6",
+    "content-hash": "4a06e0b1ef6a70cff8f6b363a0c3f4bc",
     "packages": [
         {
-            "name": "kbsali/redmine-api",
-            "version": "v1.5.21",
+            "name": "azuyalabs/yasumi",
+            "version": "2.2.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/kbsali/php-redmine-api.git",
-                "reference": "e75295b81e5dc4c858007d8924408e11e49e080c"
+                "url": "https://github.com/azuyalabs/yasumi.git",
+                "reference": "87cde7fd22e3e6e3ace9830b145b6a77338757e6"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/kbsali/php-redmine-api/zipball/e75295b81e5dc4c858007d8924408e11e49e080c",
-                "reference": "e75295b81e5dc4c858007d8924408e11e49e080c",
+                "url": "https://api.github.com/repos/azuyalabs/yasumi/zipball/87cde7fd22e3e6e3ace9830b145b6a77338757e6",
+                "reference": "87cde7fd22e3e6e3ace9830b145b6a77338757e6",
                 "shasum": ""
             },
             "require": {
-                "ext-curl": "*",
                 "ext-json": "*",
-                "ext-simplexml": "*",
-                "php": "^5.4 || ^7.2"
+                "php": ">=7.1"
             },
             "require-dev": {
-                "friendsofphp/php-cs-fixer": "^2.0",
-                "phpunit/phpunit": "^4.8.36 || ^5.4.8 || ^6.0"
+                "friendsofphp/php-cs-fixer": "^2.14",
+                "fzaninotto/faker": "~1.8",
+                "mikey179/vfsstream": "~1.6",
+                "phpunit/phpunit": "~8.4"
+            },
+            "suggest": {
+                "ext-calendar": "For calculating the date of Easter"
             },
             "type": "library",
             "autoload": {
                 "psr-4": {
-                    "Redmine\\": "src/Redmine/"
+                    "Yasumi\\": "src/Yasumi/"
                 }
             },
             "notification-url": "https://packagist.org/downloads/",
@@ -42,18 +45,23 @@
             ],
             "authors": [
                 {
-                    "name": "Kevin Saliou",
-                    "email": "kevin@saliou.name",
-                    "homepage": "http://kevin.saliou.name"
+                    "name": "Sacha Telgenhof",
+                    "email": "me@sachatelgenhof.com"
                 }
             ],
-            "description": "Redmine API client",
-            "homepage": "https://github.com/kbsali/php-redmine-api",
+            "description": "Yasumi is an easy PHP Library for calculating national holidays.",
             "keywords": [
-                "api",
-                "redmine"
+                "Bank",
+                "calculation",
+                "calendar",
+                "celebration",
+                "date",
+                "holiday",
+                "holidays",
+                "national",
+                "time"
             ],
-            "time": "2019-03-15T17:37:16+00:00"
+            "time": "2019-10-06T03:09:18+00:00"
         },
         {
             "name": "phpoption/phpoption",
diff --git a/oncall.php b/oncall.php
index fdf47cd..8985246 100644
--- a/oncall.php
+++ b/oncall.php
@@ -3,17 +3,11 @@
 declare(strict_types = 1);
 require_once 'vendor/autoload.php';
 
+use Yasumi\Holiday;
 
 /* On Call Ticket Notification Script */
-
-$today = date('Ymd');
-$holidays = array(20151126, 20151127, 20151225, 20160101, 20160118, 20160215, 20160530, 20160704, 20160905, 20161010, 20161111, 20161124);
-
-if (in_array($today, $holidays)) {
-  exit(0);
-}
-
 $oncall = new oncall();
+$oncall->dateAndTimeCheck();
 $oncall->retrieveItems();
 $oncall->setEmail();
 $table = $oncall->buildMattermostTable();
@@ -35,10 +29,10 @@ class oncall {
   private $debugMode = FALSE;
 
   /**
-   * A flag to indicate at least one ticket is overdue.
+   * A flag to indicate that everyone should be notified.
    * @var bool
    */
-  private $overdue = FALSE;
+  private $everyone = FALSE;
 
   /**
    * The URL of the Redmine install.
@@ -88,7 +82,7 @@ class oncall {
 
   /**
    * Add the number of minutes since a ticket was created.
-   * Also set the overdue flag if necessary.
+   * Also set the everyone flag if necessary.
    */
   private function getMinutes(array $item) {
     // find the time since the ticket was created
@@ -103,7 +97,7 @@ class oncall {
     $item['minutes'] = $td_min;
     // Flag if any items are overdue.
     if ($td_min > 60) {
-      $this->overdue = TRUE;
+      $this->everyone = TRUE;
     }
     return $item;
   }
@@ -174,11 +168,11 @@ class oncall {
   }
 
   /**
-   * Return a Mattermost name from email, or "@channel" if there's an overdue ticket.
+   * Return a Mattermost name from email, or "@channel" if there's an everyone ticket.
    * @return string
    */
   private function findMattermostName() {
-    if ($this->overdue) {
+    if ($this->everyone) {
       return 'channel';
     }
     // Check users.csv column 1 for email; return column 2 if it matches.
@@ -201,6 +195,44 @@ class oncall {
     $this->email = trim(file_get_contents("$contactfile"));
   }
 
+
+  /**
+   * Checks whether we're responsible for on-call on this date and time.
+   */
+  public function dateAndTimeCheck() {
+    $today = new DateTime();
+    $thisYear = (int) $today->format('Y');
+    $thisHour = (int) $today->formay('H');
+
+    // Time check.
+    if ($thisHour < 10 || $thisHour > 20) {
+      // After hours.
+      exit(0);
+    }
+
+    $holidays = Yasumi\Yasumi::create('USA', $thisYear);
+    $holidays->removeHoliday('columbusDay');
+    $holidays->addHoliday(new Holiday('indigenousPeoplesDay', [
+      'en' => 'Indigenous People\'s Day',
+    ], new DateTime("second monday of october $thisYear", new DateTimeZone('America/New_York'))));
+    $holidays->addHoliday(new Holiday('dayAfterThanksgiving', [
+      'en' => 'Day After Thanksgiving',
+    ], new DateTime("fourth friday of november $thisYear", new DateTimeZone('America/New_York'))));
+
+    // Is today a holiday?
+    if ($holidays->isHoliday($today)) {
+      $this->everyone = TRUE;
+      $todaysHoliday = $holidays->on($today);
+      print_r($todaysHoliday);
+      die;
+      $this->sendToMattermost("Happy $holidayName Megaphone Tech!  There is no on-call today.")
+    }
+    // Don't do anything else if it's a holiday or weekend.
+    if (!$holidays->isWorkingDay($today))) {
+      exit(0);
+    }
+  }
+
 }
 
 /**