diff --git a/src/services/worldStateService.ts b/src/services/worldStateService.ts
index 58247130..a7b09372 100644
--- a/src/services/worldStateService.ts
+++ b/src/services/worldStateService.ts
@@ -439,11 +439,9 @@ export const pushWeeklyActs = (
         const weekStart = EPOCH + week * unixTimesInMs.week;
         const weekEnd = weekStart + unixTimesInMs.week;
         const nightwaveWeekStart = ((): number => {
-            const nightwaveStartDate = new Date(nightwaveStartTimestamp);
-            const dayOffset = (nightwaveStartDate.getUTCDay() + 6) % 7;
-            nightwaveStartDate.setUTCDate(nightwaveStartDate.getUTCDate() - dayOffset);
-            nightwaveStartDate.setUTCHours(0, 0, 0, 0);
-            return nightwaveStartDate.getTime();
+            let ts = nightwaveStartTimestamp - EPOCH;
+            ts -= ts % unixTimesInMs.week;
+            return EPOCH + ts;
         })();
         const nightwaveWeek = Math.trunc((weekStart - nightwaveWeekStart) / unixTimesInMs.week);
         const weeklyPermanentIndex = (nightwaveWeek * 3) % pools.weeklyPermanent.length;