diff --git a/README.md b/README.md
index 5c6a9aa..95c0cf0 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,13 @@
 # Managing LaTeX lecture notes
 
-This repository complements my [third blog post about my note taking setup](https://castel.dev/post/lecture-notes-3).
+This repository complements my [third blog post about my note taking
+setup](https://castel.dev/post/lecture-notes-3).
 
-To get the calendar script working, follow step 1 and 2 of the [Google Calendar Python Quickstart](https://developers.google.com/calendar/quickstart/python), and place `credentials.json` in the `scripts` directory.
+
+## Setup Google Calendar integration
+
+To get the calendar script (`countdown.py`) working, follow step 1 and 2 of the [Google
+Calendar Python Quickstart](https://developers.google.com/calendar/quickstart/python), and
+place `credentials.json` in the `scripts` directory.
+Then open `config.py` and edit the `ROOT` as well as the `USERCALENDARID`
+variables to your own needs. 
diff --git a/scripts/config.py b/scripts/config.py
index aadc344..3db98e0 100644
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -4,6 +4,13 @@ from pathlib import Path
 def get_week(d=datetime.today()):
     return (int(d.strftime("%W")) + 52 - 5) % 52
 
+# default is 'primary', if you are using a separate calendar for your course schedule,
+# your calendarId (which you can find by going to your Google Calendar settings, selecting
+# the relevant calendar and scrolling down to Calendar ID) probably looks like
+# xxxxxxxxxxxxxxxxxxxxxxxxxg@group.calendar.google.com
+# example:
+# USERCALENDARID = 'xxxxxxxxxxxxxxxxxxxxxxxxxg@group.calendar.google.com'
+USERCALENDARID = 'primary'
 CURRENT_COURSE_SYMLINK = Path('~/current_course').expanduser()
 CURRENT_COURSE_ROOT = CURRENT_COURSE_SYMLINK.resolve()
 CURRENT_COURSE_WATCH_FILE = Path('/tmp/current_course').resolve()
diff --git a/scripts/countdown.py b/scripts/countdown.py
index 5a604c3..dfc26df 100755
--- a/scripts/countdown.py
+++ b/scripts/countdown.py
@@ -21,6 +21,7 @@ from google_auth_oauthlib.flow import InstalledAppFlow
 from google.auth.transport.requests import Request
 
 from courses import Courses
+from config import USERCALENDARID
 
 courses = Courses()
 
@@ -58,7 +59,7 @@ def join(*args):
 def truncate(string, length):
     ellipsis = ' ...'
     if len(string) < length:
-        return string 
+        return string
     return string[:length - len(ellipsis)] + ellipsis
 
 def summary(text):
@@ -186,7 +187,7 @@ def main():
             if 'dateTime' in event['start']
         ]
 
-    events = get_events('primary')
+    events = get_events(userCalendarId)
     # events = get_events('primary') + get_events('school-calendar@import.calendar.google.com')
     print('Done')
 
@@ -197,7 +198,7 @@ def main():
         print(text(events, now))
         if now < evening:
             scheduler.enter(DELAY, 1, print_message)
-    
+
     for event in events:
         # absolute entry, priority 1
         scheduler.enterabs(event['start'].timestamp(), 1, activate_course, argument=(event, ))
@@ -205,7 +206,7 @@ def main():
     # Immediate, priority 1
     scheduler.enter(0, 1, print_message)
     scheduler.run()
-    
+
 
 def wait_for_internet_connection(url, timeout=1):
     while True: