Solve monthly overflow as reported in #399

Author: bouwew

plugwise_usb/nodes/circle.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from asyncio import CancelledError, Task, create_task, gather, sleep
+import calendar
 from collections.abc import Awaitable, Callable
 from dataclasses import replace
 from datetime import UTC, datetime, timedelta
@@ -881,8 +882,13 @@ async def clock_synchronize(self) -> bool:
 
         dt_now = datetime.now(tz=UTC)
         days_diff = (response.day_of_week.value - dt_now.weekday()) % 7
+        last_day_of_month = calendar.monthrange(dt_now.year, dt_now.month)[1]
+        days_to_end_of_month = last_day_of_month - dt_now.day
+        corrected_day = dt_now.day + days_diff
+        if (difference := days_diff - days_to_end_of_month) > 0:
+            corrected_day = difference
         circle_timestamp: datetime = dt_now.replace(
-            day=dt_now.day + days_diff,
+            day=corrected_day,
             hour=response.time.value.hour,
             minute=response.time.value.minute,
             second=response.time.value.second,