diff --git a/docs/TESTPLAN.md b/docs/TESTPLAN.md
index ea1c4d9..f6efbe7 100644
--- a/docs/TESTPLAN.md
+++ b/docs/TESTPLAN.md
@@ -84,7 +84,7 @@ No user interface elements are modified in this study.
 - Install the add-on as per above
 - Verify that the study runs
 - Quit Firefox
-- Adjust the system clock so that the study is just about to have run for 14 days
+- Adjust the system clock so that the study is just about to have run for 21 days
 - Start Firefox
 - Verify that the study runs
 - Verify that the study add-on log out includes "We have entered the slumber period. Do not activate the study but schedule the re-activation"
@@ -102,7 +102,7 @@ No user interface elements are modified in this study.
 - Install the add-on as per above
 - Verify that the study runs
 - Quit Firefox
-- Adjust the system clock so that the study has run for 16 days
+- Adjust the system clock so that the study has run for 22 days
 - Start Firefox
 - Verify that the study runs
 - Verify that the study add-on log out includes "We are back after the slumber, simply activate the study and wait for study to expire"
diff --git a/src/background.js b/src/background.js
index 67b115f..fb5723c 100644
--- a/src/background.js
+++ b/src/background.js
@@ -34,7 +34,7 @@
 
 let studyLengthInDays;
 const defaultSlumberStartDay = 7;
-const defaultSlumberEndDay = 14;
+const defaultSlumberEndDay = 21;
 
 class StudyLifeCycleHandler {
   /**
diff --git a/src/studySetup.js b/src/studySetup.js
index 06152f0..ffeaf75 100644
--- a/src/studySetup.js
+++ b/src/studySetup.js
@@ -81,7 +81,7 @@ const baseStudySetup = {
 
   // maximum time that the study should run, from the first run
   expire: {
-    days: 7 * 3, // 3 weeks
+    days: 7+14+2,
   },
 };