Since a problem with my BT email account (hacked) and its restoration I only seem able to sync between the two calendars when the diary entry is ticked as a whole day event. This appears to happen in both directions. In other words try to log an event with start and end times and it does not get synced to the other diary (and visa versa). I also suspect that the times of the two systems are not in sync but cannot find where to check them both. I assume that they both access W11 for the data. Any thoughts much appreciated.