Thanks Mark, I will give it a proper look, with some varying settings of time zones, tomorrow.

On a very quick look, it seems good. I have two comments though ...

1. for 'all day' events, you are showing the time (as 00:00) which wasn't shown before and probably should not be showing now.

2. the new coding still ignores my preference setting for the date display. This is unchanged from before so may be intended? If it is intended, I will submit it as a separate bug :-)