diff --git a/analytics/classes/local/time_splitting/accumulative_parts.php b/analytics/classes/local/time_splitting/accumulative_parts.php
new file mode 100644
index 00000000000..f1b06b37cd6
--- /dev/null
+++ b/analytics/classes/local/time_splitting/accumulative_parts.php
@@ -0,0 +1,72 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Range processor splitting the course in parts and accumulating data from the start.
+ *
+ * @package   core_analytics
+ * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_analytics\local\time_splitting;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Range processor splitting the course in parts and accumulating data from the start.
+ *
+ * @package   core_analytics
+ * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+abstract class accumulative_parts extends base {
+
+    /**
+     * The number of parts to split the analysable duration in.
+     *
+     * @return int
+     */
+    abstract protected function get_number_parts();
+
+    /**
+     * define_ranges
+     *
+     * @return array
+     */
+    protected function define_ranges() {
+
+        $nparts = $this->get_number_parts();
+
+        $rangeduration = intval(floor(($this->analysable->get_end() - $this->analysable->get_start()) / $nparts));
+
+        $ranges = array();
+        for ($i = 0; $i < $nparts; $i++) {
+            $end = $this->analysable->get_start() + ($rangeduration * ($i + 1));
+            if ($i === ($nparts - 1)) {
+                // Better to use the end for the last one as we are using floor above.
+                $end = $this->analysable->get_end();
+            }
+            $ranges[$i] = array(
+                'start' => $this->analysable->get_start(),
+                'end' => $end,
+                'time' => $end
+            );
+        }
+
+        return $ranges;
+    }
+}
diff --git a/analytics/classes/local/time_splitting/deciles.php b/analytics/classes/local/time_splitting/deciles.php
index dbfca557c29..2bbd3300834 100644
--- a/analytics/classes/local/time_splitting/deciles.php
+++ b/analytics/classes/local/time_splitting/deciles.php
@@ -33,7 +33,7 @@ defined('MOODLE_INTERNAL') || die();
  * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class deciles extends base {
+class deciles extends equal_parts {
 
     /**
      * get_name
@@ -45,27 +45,11 @@ class deciles extends base {
     }
 
     /**
-     * define_ranges
+     * 10 parts.
      *
-     * @return array
+     * @return int
      */
-    protected function define_ranges() {
-        $rangeduration = floor(($this->analysable->get_end() - $this->analysable->get_start()) / 10);
-
-        $ranges = array();
-        for ($i = 0; $i < 10; $i++) {
-            $start = $this->analysable->get_start() + ($rangeduration * $i);
-            $end = $this->analysable->get_start() + ($rangeduration * ($i + 1));
-            if ($i === 9) {
-                $end = $this->analysable->get_end();
-            }
-            $ranges[] = array(
-                'start' => $start,
-                'end' => $end,
-                'time' => $end
-            );
-        }
-
-        return $ranges;
+    protected function get_number_parts() {
+        return 10;
     }
 }
diff --git a/analytics/classes/local/time_splitting/deciles_accum.php b/analytics/classes/local/time_splitting/deciles_accum.php
index 486be855334..0f7e706743a 100644
--- a/analytics/classes/local/time_splitting/deciles_accum.php
+++ b/analytics/classes/local/time_splitting/deciles_accum.php
@@ -33,7 +33,7 @@ defined('MOODLE_INTERNAL') || die();
  * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class deciles_accum extends base {
+class deciles_accum extends accumulative_parts {
 
     /**
      * get_name
@@ -45,26 +45,11 @@ class deciles_accum extends base {
     }
 
     /**
-     * define_ranges
+     * 10 parts.
      *
-     * @return array
+     * @return int
      */
-    protected function define_ranges() {
-        $rangeduration = floor(($this->analysable->get_end() - $this->analysable->get_start()) / 10);
-
-        $ranges = array();
-        for ($i = 0; $i < 10; $i++) {
-            $end = $this->analysable->get_start() + ($rangeduration * ($i + 1));
-            if ($i === 9) {
-                $end = $this->analysable->get_end();
-            }
-            $ranges[] = array(
-                'start' => $this->analysable->get_start(),
-                'end' => $end,
-                'time' => $end
-            );
-        }
-
-        return $ranges;
+    protected function get_number_parts() {
+        return 10;
     }
 }
diff --git a/analytics/classes/local/time_splitting/equal_parts.php b/analytics/classes/local/time_splitting/equal_parts.php
new file mode 100644
index 00000000000..090e693fe35
--- /dev/null
+++ b/analytics/classes/local/time_splitting/equal_parts.php
@@ -0,0 +1,80 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * X parts time splitting method.
+ *
+ * @package   core_analytics
+ * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_analytics\local\time_splitting;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * X parts time splitting method.
+ *
+ * @package   core_analytics
+ * @copyright 2017 David Monllao {@link http://www.davidmonllao.com}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+abstract class equal_parts extends base {
+
+    /**
+     * Returns the number of parts the analyser duration should be split in.
+     *
+     * @return int
+     */
+    abstract protected function get_number_parts();
+
+    /**
+     * Splits the analysable duration in X equal parts from the start to the end.
+     *
+     * @return array
+     */
+    protected function define_ranges() {
+
+        $nparts = $this->get_number_parts();
+
+        $rangeduration = intval(floor(($this->analysable->get_end() - $this->analysable->get_start()) / $nparts));
+
+        $ranges = array();
+        for ($i = 0; $i < $nparts; $i++) {
+            $start = $this->analysable->get_start() + ($rangeduration * $i);
+            $end = $this->analysable->get_start() + ($rangeduration * ($i + 1));
+
+            // Check the end of the previous time range.
+            if ($i > 0 && $start === $ranges[$i - 1]['end']) {
+                // We deduct 1 second from the previous end so each timestamp only belongs to 1 range.
+                $ranges[$i - 1]['end'] = $ranges[$i - 1]['end'] - 1;
+            }
+
+            if ($i === ($nparts - 1)) {
+                // Better to use the end for the last one as we are using floor above.
+                $end = $this->analysable->get_end();
+            }
+            $ranges[$i] = array(
+                'start' => $start,
+                'end' => $end,
+                'time' => $end
+            );
+        }
+
+        return $ranges;
+    }
+}
diff --git a/analytics/classes/local/time_splitting/quarters.php b/analytics/classes/local/time_splitting/quarters.php
index 4ad1b5f3681..3a8340bebdd 100644
--- a/analytics/classes/local/time_splitting/quarters.php
+++ b/analytics/classes/local/time_splitting/quarters.php
@@ -15,7 +15,7 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
- * 4 quarters time splitting method.
+ * Quarters time splitting method.
  *
  * @package   core_analytics
  * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
@@ -27,13 +27,13 @@ namespace core_analytics\local\time_splitting;
 defined('MOODLE_INTERNAL') || die();
 
 /**
- * 4 quarters time splitting method.
+ * Quarters time splitting method.
  *
  * @package   core_analytics
  * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class quarters extends base {
+class quarters extends equal_parts {
 
     /**
      * get_name
@@ -45,30 +45,11 @@ class quarters extends base {
     }
 
     /**
-     * define_ranges
+     * 4 parts
      *
-     * @return array
+     * @return int
      */
-    protected function define_ranges() {
-        $duration = floor(($this->analysable->get_end() - $this->analysable->get_start()) / 4);
-        return [
-            [
-                'start' => $this->analysable->get_start(),
-                'end' => $this->analysable->get_start() + $duration,
-                'time' => $this->analysable->get_start() + $duration
-            ], [
-                'start' => $this->analysable->get_start() + $duration,
-                'end' => $this->analysable->get_start() + ($duration * 2),
-                'time' => $this->analysable->get_start() + ($duration * 2)
-            ], [
-                'start' => $this->analysable->get_start() + ($duration * 2),
-                'end' => $this->analysable->get_start() + ($duration * 3),
-                'time' => $this->analysable->get_start() + ($duration * 3)
-            ], [
-                'start' => $this->analysable->get_start() + ($duration * 3),
-                'end' => $this->analysable->get_end(),
-                'time' => $this->analysable->get_end()
-            ]
-        ];
+    protected function get_number_parts() {
+        return 4;
     }
 }
diff --git a/analytics/classes/local/time_splitting/quarters_accum.php b/analytics/classes/local/time_splitting/quarters_accum.php
index 6b7e0fc692b..d8fb0d9c405 100644
--- a/analytics/classes/local/time_splitting/quarters_accum.php
+++ b/analytics/classes/local/time_splitting/quarters_accum.php
@@ -33,7 +33,7 @@ defined('MOODLE_INTERNAL') || die();
  * @copyright 2016 David Monllao {@link http://www.davidmonllao.com}
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-class quarters_accum extends base {
+class quarters_accum extends accumulative_parts {
 
     /**
      * get_name
@@ -45,30 +45,11 @@ class quarters_accum extends base {
     }
 
     /**
-     * define_ranges
+     * 4 parts.
      *
-     * @return array
+     * @return int
      */
-    protected function define_ranges() {
-        $duration = floor(($this->analysable->get_end() - $this->analysable->get_start()) / 4);
-        return [
-            [
-                'start' => $this->analysable->get_start(),
-                'end' => $this->analysable->get_start() + $duration,
-                'time' => $this->analysable->get_start() + $duration
-            ], [
-                'start' => $this->analysable->get_start(),
-                'end' => $this->analysable->get_start() + ($duration * 2),
-                'time' => $this->analysable->get_start() + ($duration * 2)
-            ], [
-                'start' => $this->analysable->get_start(),
-                'end' => $this->analysable->get_start() + ($duration * 3),
-                'time' => $this->analysable->get_start() + ($duration * 3)
-            ], [
-                'start' => $this->analysable->get_start(),
-                'end' => $this->analysable->get_end(),
-                'time' => $this->analysable->get_end()
-            ]
-        ];
+    protected function get_number_parts() {
+        return 4;
     }
 }