diff --git a/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime.ts b/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime.ts
index a8dd8e2..54776b6 100644
--- a/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime.ts
+++ b/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime.ts
@@ -26,6 +26,9 @@ export const getRoundedTimestamp = () => {
   return now - (now % (1000 * 60 * 60 * 24 * 2 /* 2 days */))
 }
 
+const dayLengthInMinutes = MinuteOfDay.LENGTH
+const dayLengthInMs = dayLengthInMinutes * 1000 * 60
+
 export async function dispatchAddUsedTime ({ deviceId, action, cache }: {
   deviceId: string
   action: AddUsedTimeAction
@@ -63,7 +66,7 @@ export async function dispatchAddUsedTime ({ deviceId, action, cache }: {
     if (action.timeToAdd !== 0) {
       // try to update first
       const [updatedRows] = await cache.database.usedTime.update({
-        usedTime: Sequelize.literal(`usedTime + ${action.timeToAdd}`) as any,
+        usedTime: Sequelize.literal(`MAX(0, MIN(usedTime + ${action.timeToAdd}, ${dayLengthInMs}))`) as any,
         lastUpdate: roundedTimestamp
       }, {
         where: {
@@ -82,7 +85,7 @@ export async function dispatchAddUsedTime ({ deviceId, action, cache }: {
           familyId: cache.familyId,
           categoryId: categoryId,
           dayOfEpoch: action.dayOfEpoch,
-          usedTime: action.timeToAdd,
+          usedTime: Math.min(action.timeToAdd, dayLengthInMs),
           lastUpdate: roundedTimestamp,
           startMinuteOfDay: MinuteOfDay.MIN,
           endMinuteOfDay: MinuteOfDay.MAX
diff --git a/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime2.ts b/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime2.ts
index 76b6b53..2cc3233 100644
--- a/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime2.ts
+++ b/src/function/sync/apply-actions/dispatch-app-logic-action/addusedtime2.ts
@@ -64,9 +64,12 @@ export async function dispatchAddUsedTimeVersion2 ({ deviceId, action, cache }:
 
     // tslint:disable-next-line:no-inner-declarations
     async function handle (start: number, end: number) {
+      const lengthInMinutes = (end - start) + 1
+      const lengthInMs = lengthInMinutes * 1000 * 60
+
       // try to update first
       const [updatedRows] = await cache.database.usedTime.update({
-        usedTime: Sequelize.literal(`usedTime + ${item.timeToAdd}`) as any,
+        usedTime: Sequelize.literal(`MAX(0, MIN(usedTime + ${item.timeToAdd}, ${lengthInMs}))`) as any,
         lastUpdate: roundedTimestampForUsedTime
       }, {
         where: {
@@ -85,7 +88,7 @@ export async function dispatchAddUsedTimeVersion2 ({ deviceId, action, cache }:
           familyId: cache.familyId,
           categoryId: item.categoryId,
           dayOfEpoch: action.dayOfEpoch,
-          usedTime: item.timeToAdd,
+          usedTime: Math.min(item.timeToAdd, lengthInMs),
           lastUpdate: roundedTimestampForUsedTime,
           startMinuteOfDay: start,
           endMinuteOfDay: end