Timezone information changes unexpectedly when editing reminders

I created a reminder via twitter with a time and date, but wanted the reminder interval to be the day before instead of the usual 15 minutes.

I went to the website, selected the reminder and chose edit. (At this point the reminder looks fine - Tuesday 8th January at 09:45 GMT).

I changed the reminder interval and saved and the task ended up at 5:45pm PST (which makes no sense).

I tried to change the date back, but the reminder got moved to 1st August 2008 this time with a EST timezone.

My settings are Europe - London and DD/MM/YYYY (changing to US format dates helps a little, but I really don't want to change to a US timezone).
 
sad I’m confused
Inappropriate?
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