diff --git a/amd/src/string-helper.js b/amd/src/string-helper.js
index 6d4f38a..c2b57f7 100644
--- a/amd/src/string-helper.js
+++ b/amd/src/string-helper.js
@@ -72,4 +72,48 @@ export function format_date(d,short){
     return d.toLocaleDateString(document.documentElement.lang,{
         year: 'numeric', month: monthformat, day: 'numeric'
     });
-}
\ No newline at end of file
+}
+
+/**
+ * Provides standardized information about the period between two dates
+ * As
+ * @param {Date|string} first First day of the span
+ * @param {Date|string} last Last day of the span
+ * @returns {Object} Object containing formatted start and end dates and span information
+ */
+export function datespaninfo(first,last){
+    if(!(first instanceof Date)){ first = new Date(first);}
+    if(!(last instanceof Date)){ last = new Date(last);}
+
+    // Make sure the end date is at the very end of the day and the start date at the very beginning
+    first.setHours(0);
+    first.setMinutes(0);
+    first.setSeconds(0);
+    first.setMilliseconds(0);
+    last.setHours(23);
+    last.setMinutes(59);
+    last.setSeconds(59);
+    last.setMilliseconds(999);
+
+    const dayspan = Math.round(((last - first)+1)/(24*60*60*1000)); // Add one millisecond to offset the 999 ms
+    const years = Math.floor(dayspan/365); // Yes, we ignore leap years/leap days
+    const ydaysleft = dayspan % 365;
+
+    const weeks = Math.floor(ydaysleft/7);
+    const wdaysleft = ydaysleft % 7;
+
+    return {
+        first: first,
+        last: last,
+        totaldays: dayspan,
+        years: years,
+        weeks: weeks,
+        days: wdaysleft,
+        formatted: {
+            first: format_date(first),
+            last: format_date(last),
+        }
+    };
+
+}
+
diff --git a/amd/src/studyplan-editor-components.js b/amd/src/studyplan-editor-components.js
index 403e0b4..22a7ee0 100644
--- a/amd/src/studyplan-editor-components.js
+++ b/amd/src/studyplan-editor-components.js
@@ -10,7 +10,7 @@ import {SimpleLine} from "./simpleline";
 import {call} from 'core/ajax';
 import notification from 'core/notification';
 import {get_strings} from 'core/str';
-import {load_stringkeys, load_strings, format_date} from './string-helper';
+import {load_stringkeys, load_strings, format_date, datespaninfo} from './string-helper';
 import {objCopy,transportItem} from './studyplan-processor';
 import Debugger from './debugger';
 import {download,upload} from './downloader';
@@ -148,6 +148,26 @@ export default {
                 startdate: 'studyplan_startdate',
                 enddate: 'studyplan_enddate',
             },
+            course_timing: {
+                title: 'course_timing_title',
+                desc: 'course_timing_desc',
+                question: 'course_timing_question',
+                warning: 'course_timing_warning',
+                course: 'course$core',
+                period: 'period',
+                yes: 'yes$core',
+                no: 'no$core',
+                duration: 'duration',
+                years: 'years$core',
+                year: 'year$core',
+                weeks: 'weeks$core',
+                week: 'week$core',
+                days: 'days$core',
+                day: 'day$core',
+                rememberchoice: 'course_timing_rememberchoice',
+                hidewarning: 'course_timing_hidewarning,'
+
+            },
             studyplan_associate: {
                 associations: 'associations',
                 associated_cohorts: 'associated_cohorts',
@@ -1526,6 +1546,7 @@ export default {
                                         :line="line"
                                         :plan="value"
                                         :page="page"
+                                        :period="page.perioddesc[index-1]"
                                         :layer="layeridx-1"
                                         :class="'t-studyline ' + ((lineindex%2==0)?' odd ':' even ')
                                                 + ((lineindex==0 && layeridx==1)?' first ':' ')
@@ -1787,7 +1808,14 @@ export default {
                     type: Object, // Studyplan data
                     default(){ return null;},
                 },
-                
+                page: {
+                    type: Object, // Studyplan data
+                    default(){ return null;},
+                },
+                period: {
+                    type: Object, // Studyplan data
+                    default(){ return null;},
+                },                
             },
             mounted() {
                 const self=this;
@@ -1807,6 +1835,9 @@ export default {
                 }
             },
             computed: {
+                slotkey(){
+                    return `${this.type}'-'${this.line.id}-${this.slotindex}-${this.layer}`;
+                },
                 item(){
                     for(const ix in this.value){
                         const itm = this.value[ix];
@@ -1832,10 +1863,18 @@ export default {
             },
             data() {
                 return {
+                    text: strings.course_timing,
                     resizeListener: null,
                     hover: { 
                         component:null,
                         type: null,
+                    },
+                    datechanger: {
+                        coursespan: null,
+                        periodspan: null,
+                        default: false,
+                        defaultchoice: false,
+                        hidewarn: false,
                     }
                 };
             },
@@ -1861,15 +1900,18 @@ export default {
                     const self = this;
                     if(self.dragacceptitem().includes(event.type)) {
                         let item = event.data;
+                        
                         // Perform layer update - set this slot and layer here
                         self.relocateStudyItem(item).done(()=>{
                             item.layer = this.layer;
                             item.slot = this.slotindex;
                             self.value.push(item);
-                            self.$emit("input",self.value);                    
-                        });
+                            self.$emit("input",self.value);
+                            self.validate_course_period();
+                        });          
                     }
                     else if(self.dragacceptcomponent().includes(event.type) ){
+
                         if(event.type == "course"){
                             call([{
                                 methodname: 'local_treestudyplan_add_studyitem',
@@ -1891,7 +1933,8 @@ export default {
                                 let item = response;
                                 self.relocateStudyItem(item).done(()=>{
                                     self.value.push(item);
-                                    self.$emit("input",self.value);                    
+                                    self.$emit("input",self.value);
+                                    self.validate_course_period();
                                 });
                             }).fail(notification.exception);
                         }                 
@@ -1944,7 +1987,58 @@ export default {
                     this.hover.component = null;
                     this.hover.type = null;
                 },
+                validate_course_period() {
+                    const self = this;
+                    debug.info("Validating course and period",self.item,self.period);
+                    if(self.item && self.item.type == 'course'){
+                        self.datechanger.coursespan = datespaninfo(self.item.course.startdate,self.item.course.enddate);
+                        self.datechanger.periodspan = datespaninfo(self.period.startdate,self.period.enddate);
+                        if( self.datechanger.coursespan.first != self.datechanger.periodspan.first 
+                            || self.datechanger.coursespan.last != self.datechanger.periodspan.last  ){
+                            debug.info("Course timing does not match period timing");
 
+                            if(self.item.course.canupdatecourse){
+                                if(!self.datechanger.default){
+                                    // Periods do not match, pop up the date change request 
+                                    this.$bvModal.show("t-course-date-matching-"+this.slotkey);
+                                } else if (self.datechanger.defaultvalue){
+                                    // go for it without asking
+                                    self.change_course_period();
+                                }
+                            }
+                            else {
+                                // user is not able to change course timing - show a warning
+                                if(!self.datechanger.hidewarn){
+                                    this.$bvModal.show("t-course-date-warning-"+this.slotkey);
+                                }
+                            }
+                        }
+                        else {
+                            debug.info("Course timing matches period",self.datechanger);
+                        }
+                    }
+                },
+                change_course_period() {
+                    const self=this;
+                    return call([{
+                        methodname: 'local_treestudyplan_course_period_timing',
+                        args: { page_id: self.page_id,
+                                period: self.period.period, 
+                                course_id: this.item.course.id,
+                            }
+                    }])[0].fail(notification.exception);  
+                },
+                format_duration(dsi){
+                    let s = "";
+                    if(dsi.years == 1){ s += `1 ${this.text.year}, `;}
+                    else if(dsi.years > 1){ s += `${dsi.years} ${this.text.years}, `;}
+                    if(dsi.weeks == 1){ s += `1 ${this.text.week}, `;}
+                    else if(dsi.weeks > 1){ s += `${dsi.weeks} ${this.text.weeks}, `;}
+                    if(dsi.days == 1){ s += `1 ${this.text.day}, `;}
+                    else if(dsi.days > 1){ s += `${dsi.days} ${this.text.days}, `;}
+
+                    return s.toLocaleLowerCase();
+                }
             },
             template: `
             <div :class="'t-studyline-slot '+type + ' t-studyline-slot-'+slotindex + ' ' + ((slotindex==0)?' t-studyline-firstcolumn ':' ')"
@@ -1987,8 +2081,77 @@ export default {
                             class="t-slot-item feedback"
                             :key="hover.type">--{{ hover.type }}--</div
                     ></template
-                ></drop
-            ></div>
+                ></drop>
+                <b-modal 
+                    :id="'t-course-date-matching-'+this.slotkey" 
+                    size="lg" 
+                    :title="text.title"
+                    @ok="change_course_period"
+                    :ok-title="text.yes"
+                    cancel-disabled
+                    >
+                    <b-container v-if="datechanger.coursespan && datechanger.periodspan && item && item.course">
+                        <b-row><b-col cols="12">{{ text.desc }}</b-col></b-row>
+                        <b-row><b-col cols="12"><div class="generalbox alert alert-warning">{{ text.question }}</div></b-col></b-row>
+                        <b-row>
+                            <b-col cols="6">
+                                <h3> {{ text.course }} </h3>
+                                <p><b>{{ item.course.fullname }}</b></p>
+                                <p><b>{{ item.course.shortname }}</b></p>
+                                <p>{{ datechanger.coursespan.formatted.first}} - {{ datechanger.coursespan.formatted.last}}</p>
+                                <p><b>{{ text.duration }}</b><br>
+                                {{ format_duration(datechanger.coursespan)}}</p>
+                            </b-col>
+                            <b-col cols="6">
+                                <h3> {{ text.period }} </h3>
+                                <p><b>{{ period.fullname }}</b></p>
+                                <p><b>{{ period.shortname }}</b></p>
+                                <p>{{ datechanger.periodspan.formatted.first}} - {{ datechanger.periodspan.formatted.last}}</p>
+                                <p><b>{{ text.duration }}</b><br>
+                                {{ format_duration(datechanger.periodspan)}}</p>
+                            </b-col>
+                        </b-row>
+                        <b-row><b-col cols="12">
+                            <b-form-checkbox type="checkbox" v-model="datechanger.default">{{ text.rememberchoice }}</b-form-checkbox>
+                        </b-col></b-row>
+                    </b-container>
+                </b-modal>
+                <b-modal 
+                    :id="'t-course-date-warning-'+this.slotkey" 
+                    size="lg" 
+                    ok-variant="danger"
+                    :title="text.title"
+                    :ok-title="text.yes"
+                    :cancel-title="text.no"
+                    cancel-variant="primary"                    
+                    >
+                    <b-container v-if="datechanger.coursespan && datechanger.periodspan && item && item.course">
+                        <b-row><b-col cols="12">{{ text.desc }}</b-col></b-row>
+                        <b-row><b-col cols="12"><div class="generalbox alert alert-warning">{{ text.warning }}</div></b-col></b-row>
+                        <b-row>
+                            <b-col cols="6">
+                                <h3> {{ text.course }} </h3>
+                                <p><b>{{ item.course.fullname }}</b></p>
+                                <p><b>{{ item.course.shortname }}</b></p>
+                                <p>{{ datechanger.coursespan.formatted.first}} - {{ datechanger.coursespan.formatted.last}}</p>
+                                <p><b>{{ text.duration }}</b><br>
+                                {{ format_duration(datechanger.coursespan)}}</p>
+                            </b-col>
+                            <b-col cols=>"6">
+                                <h3> {{ text.period }} </h3>
+                                <p><b>{{ period.fullname }}</b></p>
+                                <p><b>{{ period.shortname }}</b></p>
+                                <p>{{ datechanger.periodspan.formatted.first}} - {{ datechanger.periodspan.formatted.last}}</p>
+                                <p><b>{{ text.duration }}</b><br>
+                                {{ format_duration(datechanger.periodspan)}}</p>
+                            </b-col>
+                        </b-row>
+                        <b-row><b-col cols="12">
+                            <b-form-checkbox type="checkbox" v-model="datechanger.hidewarn">{{ text.hidewarning }}</b-form-checkbox>
+                        </b-col></b-row>
+                    </b-container>
+                </b-modal>
+            </div>
             `,
         });
 
diff --git a/amd/src/treestudyplan-components.js b/amd/src/treestudyplan-components.js
index 727bf61..9368454 100644
--- a/amd/src/treestudyplan-components.js
+++ b/amd/src/treestudyplan-components.js
@@ -175,7 +175,7 @@ export default {
                     >{{ value.fullname }}<br>
                     <span class="s-studyline-header-period-datespan">
                         <span class="date">{{ startdate }}</span> - <span class="date">{{ enddate }}</span>
-                    <span>
+                    </span>
                 </b-tooltip>
                 <slot></slot
                 ><p class="s-studyline-header-period-datespan small">
diff --git a/classes/courseinfo.php b/classes/courseinfo.php
index dce3b94..419891e 100644
--- a/classes/courseinfo.php
+++ b/classes/courseinfo.php
@@ -178,6 +178,7 @@ class courseinfo {
             "startdate" => new \external_value(PARAM_TEXT, 'Course start date'),
             "enddate" => new \external_value(PARAM_TEXT, 'Course end date'),
             "amteacher" => new \external_value(PARAM_BOOL, 'Requesting user is teacher in this course'),
+            "canupdatecourse" => new \external_value(PARAM_BOOL, "If the current user can update this course"),
             "canselectgradables" => new \external_value(PARAM_BOOL, 'Requesting user can change selected gradables'),
             "tag" => new \external_value(PARAM_TEXT, 'Tag'),
         ], 'referenced course information',$value);
@@ -200,6 +201,7 @@ class courseinfo {
             'startdate' => date("Y-m-d",$this->course->startdate,), 
             'enddate' => date("Y-m-d",$this->course->enddate),            
             'amteacher' => $this->amTeacher(),
+            'canupdatecourse' => \has_capability("moodle/course:update",$this->coursecontext),
             'canselectgradables' =>  $this->iCanSelectGradables(),
             'tag' => "Editormodel",
             'grades' => [],
diff --git a/classes/studyplanservice.php b/classes/studyplanservice.php
index cb825d5..bfcea46 100644
--- a/classes/studyplanservice.php
+++ b/classes/studyplanservice.php
@@ -1179,6 +1179,44 @@ class studyplanservice extends \external_api
  
      }
 
+     /************************
+     *                      *
+     * edit_period       *  
+     *                      *
+     ************************/
+
+     public static function course_period_timing_parameters() 
+     {
+         return new \external_function_parameters( [
+             "page_id" => new \external_value(PARAM_INT, 'Studyplan page id'),
+             "period" => new \external_value(PARAM_INT, 'Period number within page'),
+             "course_id"=> new \external_value(PARAM_INT, 'Id of course to adjust dates for'),
+         ]);
+     }
+ 
+     public static function course_period_timing_returns() 
+     {
+         return success::structure();
+     }
+     public static function course_period_timing($page_id, $period, $course_id){
+        $page = studyplanpage::findById($page_id);
+        $course = \get_course($course_id);
+        $coursecontext = \context_course::instance($course_id);
+        // Check for studyplan edit permissions
+        webservicehelper::require_capabilities(self::CAP_EDIT,$page->studyplan()->context());
+        
+        if(webservicehelper::has_capabilities("moodle/course:update",$coursecontext)){
+            //TODO: Actually perform the timing changes, while also updating the module times
+            // Like what happens on a course "reset"
+
+
+            return success::success()->model();
+        } else {
+            // probably should return a nice message
+            return success::fail("You do not have date change permissions on this course")->model();
+        }
+
+     }
 
 
 }
\ No newline at end of file
diff --git a/lang/en/local_treestudyplan.php b/lang/en/local_treestudyplan.php
index b5fb924..959973d 100644
--- a/lang/en/local_treestudyplan.php
+++ b/lang/en/local_treestudyplan.php
@@ -290,4 +290,12 @@ $string["badgeinfo"] = "Badge details";
 $string["badgeissuedstats"] = "Issuing progress";
 
 $string["period_default_fullname"] = 'Period {$a}';
-$string["period_default_shortname"] = 'P{$a}';
\ No newline at end of file
+$string["period_default_shortname"] = 'P{$a}';
+$string["course_timing_title"] = 'Course timing does not match period timing';
+$string["course_timing_desc"] = 'The start and end date of the course you are dropping into this period does not match the start and end date of the period.';
+$string["course_timing_question"] = 'Do you want to update the course\'s start and end time to match that of the period?';
+$string["course_timing_warning"] = 'You do not have permission to automatically update this course start and end date. Automatic timing update not available';
+$string["period"] = 'Period';
+$string["duration"] = 'Duration';
+$string["course_timing_rememberchoice"] = 'Remember my choice for future date mismatches';
+$string["course_timing_hidewarning"] = 'Hide this warning next time';
\ No newline at end of file
diff --git a/lang/nl/local_treestudyplan.php b/lang/nl/local_treestudyplan.php
index a071afe..48c40d0 100644
--- a/lang/nl/local_treestudyplan.php
+++ b/lang/nl/local_treestudyplan.php
@@ -293,4 +293,12 @@ $string["badgeinfo"] = "Meer details";
 $string["badgeissuedstats"] = "Voortgang van uitgifte";
 
 $string["period_default_fullname"] = 'Periode {$a}';
-$string["period_default_shortname"] = 'P{$a}';
\ No newline at end of file
+$string["period_default_shortname"] = 'P{$a}';
+$string["course_timing_title"] = 'Cursustiming en periodetiming komen niet overeen';
+$string["course_timing_desc"] = 'De start- en einddatum van de cursus, komen niet overen met die van de periode waarin je hem hebt gedropt.';
+$string["course_timing_question"] = 'Wil je de start- en eindtijd van de cursus aanpassen naar doe van de periode?';
+$string["course_timing_warning"] = 'Je hebt geen rechten om de start- en eindtijd van deze cursus aan te passen. Aanpassen van cursus naar periodetiming is niet beschikbaar.';
+$string["period"] = 'Periode';
+$string["duration"] = 'Duur';
+$string["course_timing_rememberchoice'"] = 'Onthoud mijn keuze voor toekomstige mismatches tussen cursus en periode';
+$string["course_timing_hidewarning"] = 'Hide this warning next time';
\ No newline at end of file