diff --git a/composeApp/src/commonMain/kotlin/com/derakkuma/data/MaintenanceMode.kt b/composeApp/src/commonMain/kotlin/com/derakkuma/data/MaintenanceMode.kt
index 874a7a3..ddf97db 100644
--- a/composeApp/src/commonMain/kotlin/com/derakkuma/data/MaintenanceMode.kt
+++ b/composeApp/src/commonMain/kotlin/com/derakkuma/data/MaintenanceMode.kt
@@ -2,37 +2,64 @@ package com.derakkuma.data
 
 import kotlin.time.Clock
 import kotlin.time.Instant
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.FixedOffsetTimeZone
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.LocalTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.UtcOffset
+import kotlinx.datetime.toInstant
+import kotlinx.datetime.toLocalDateTime
 
 /**
- * maimai DX NET maintenance window: 19:00–22:00 UTC daily.
+ * maimai DX NET maintenance window.
+ *
+ * Before 2026-09-01: 19:00–22:00 UTC daily.
+ * From 2026-09-01: 8:00–9:00 AM PST every day except Tuesdays,
+ * and 8:00–11:00 AM PST on Tuesdays (PST = fixed UTC-8).
+ *
  * During this time the server returns maintenance pages;
  * the app should show cached (read-only) data and disable all actions.
  */
 object MaintenanceMode {
-    private const val START_HOUR = 19 // 19:00 UTC
-    private const val END_HOUR = 22 // 22:00 UTC
+    private const val LEGACY_START_HOUR_UTC = 19
+    private const val LEGACY_END_HOUR_UTC = 22
 
-    fun isActive(): Boolean {
-        val hour = utcHour()
-        return hour in START_HOUR until END_HOUR
-    }
+    private val PST: TimeZone = FixedOffsetTimeZone(UtcOffset(hours = -8))
+    private val NEW_SCHEDULE_START_DATE = LocalDate(2026, 9, 1)
+
+    private const val NEW_START_HOUR = 8
+    private const val NEW_END_HOUR = 9
+    private const val NEW_END_HOUR_TUESDAY = 11
+
+    fun isActive(): Boolean = maintenanceEnd(Clock.System.now()) != null
 
     /** Seconds remaining until maintenance ends. 0 if not in maintenance. */
     fun secondsRemaining(): Long {
-        if (!isActive()) return 0L
         val now = Clock.System.now()
-        val epochSeconds = now.epochSeconds
-        // Seconds since midnight UTC
-        val secondsSinceMidnight = epochSeconds % 86400
-        // End of maintenance in seconds since midnight
-        val endSeconds = END_HOUR * 3600L
-        return (endSeconds - secondsSinceMidnight).coerceAtLeast(0)
+        val end = maintenanceEnd(now) ?: return 0L
+        return (end.epochSeconds - now.epochSeconds).coerceAtLeast(0)
     }
 
-    /** Current UTC hour (0–23). */
-    private fun utcHour(): Int {
-        val epochSeconds = Clock.System.now().epochSeconds
-        // UTC = epoch seconds; hour = (seconds / 3600) % 24
-        return ((epochSeconds / 3600) % 24).toInt()
+    /** The Instant the current maintenance window ends, or null if not in maintenance. */
+    private fun maintenanceEnd(now: Instant): Instant? {
+        val pstNow = now.toLocalDateTime(PST)
+        return if (pstNow.date >= NEW_SCHEDULE_START_DATE) {
+            val endHour =
+                if (pstNow.dayOfWeek == DayOfWeek.TUESDAY) NEW_END_HOUR_TUESDAY else NEW_END_HOUR
+            val start = LocalDateTime(pstNow.date, LocalTime(NEW_START_HOUR, 0)).toInstant(PST)
+            val end = LocalDateTime(pstNow.date, LocalTime(endHour, 0)).toInstant(PST)
+            if (now >= start && now < end) end else null
+        } else {
+            val secondsSinceMidnightUtc = now.epochSeconds % 86400
+            val startSeconds = LEGACY_START_HOUR_UTC * 3600L
+            val endSeconds = LEGACY_END_HOUR_UTC * 3600L
+            if (secondsSinceMidnightUtc in startSeconds until endSeconds) {
+                Instant.fromEpochSeconds(now.epochSeconds - secondsSinceMidnightUtc + endSeconds)
+            } else {
+                null
+            }
+        }
     }
 }