diff --git a/app/src/main/java/com/todoroo/astrid/service/Upgrader.kt b/app/src/main/java/com/todoroo/astrid/service/Upgrader.kt
index 2044d6e70..459a1c187 100644
--- a/app/src/main/java/com/todoroo/astrid/service/Upgrader.kt
+++ b/app/src/main/java/com/todoroo/astrid/service/Upgrader.kt
@@ -42,7 +42,8 @@ class Upgrader @Inject constructor(
         private val iCal: iCalendar,
         private val widgetManager: AppWidgetManager,
         private val taskMover: TaskMover,
-        private val upgraderDao: UpgraderDao) {
+        private val upgraderDao: UpgraderDao,
+        private val openTaskDao: OpenTaskDao) {
 
     fun upgrade(from: Int, to: Int) {
         if (from > 0) {
@@ -73,6 +74,7 @@ class Upgrader @Inject constructor(
             }
             run(from, V11_3) {
                 applyiCalendarStartDates()
+                applyOpenTaskStartDates()
             }
             preferences.setBoolean(R.string.p_just_updated, true)
         }
@@ -133,6 +135,27 @@ class Upgrader @Inject constructor(
                 .let { taskDao.touch(it) }
     }
 
+    private suspend fun applyOpenTaskStartDates() {
+        openTaskDao.getLists().forEach { list ->
+            val (hasStartDate, noStartDate) =
+                    upgraderDao
+                            .getOpenTasksForList(list.account!!, list.url!!)
+                            .partition { it.startDate > 0 }
+            for (task in noStartDate) {
+                openTaskDao
+                        .getTask(list.id, task.remoteId!!)
+                        ?.dtStart
+                        ?.let {
+                            it.apply(task.task)
+                            upgraderDao.setStartDate(task.id, task.startDate)
+                        }
+            }
+            hasStartDate
+                    .map { it.id }
+                    .let { taskDao.touch(it) }
+        }
+    }
+
     private suspend fun applyCaldavOrder() {
         for (task in upgraderDao.tasksWithVtodos().map(CaldavTaskContainer::caldavTask)) {
             val remoteTask = fromVtodo(task.vtodo!!) ?: continue
diff --git a/app/src/main/java/org/tasks/data/UpgraderDao.kt b/app/src/main/java/org/tasks/data/UpgraderDao.kt
index 96c884ee5..92e20c241 100644
--- a/app/src/main/java/org/tasks/data/UpgraderDao.kt
+++ b/app/src/main/java/org/tasks/data/UpgraderDao.kt
@@ -24,6 +24,16 @@ GROUP BY tasks._id
     """)
     suspend fun tasksWithTags(): List<Long>
 
+    @Query("""
+SELECT task.*, caldav_task.*
+FROM tasks AS task
+         INNER JOIN caldav_tasks AS caldav_task ON _id = cd_task
+         INNER JOIN caldav_lists ON cd_calendar = cdl_uuid
+WHERE cd_deleted = 0
+  AND cdl_account = :account AND cdl_url = :url
+    """)
+    suspend fun getOpenTasksForList(account: String, url: String): List<CaldavTaskContainer>
+
     @Query("UPDATE tasks SET hideUntil = :startDate WHERE _id = :task")
     fun setStartDate(task: Long, startDate: Long)
 }
\ No newline at end of file