Copying/pasting current Starts date into field changes Starts date

I have an RT user account whose date display format is RFC2822, and a
ticket whose Starts value is Mon, 15 Dec 2014 18:19:28 +1100.

As that user, if I go to that ticket’s Dates page, copy the Starts value
from the brackets into the text field and hit submit, the Starts value
rewinds by 11 hours (the GMT offset of the RT installation):

Starts changed from Mon, 15 Dec 2014 18:19:28 +1100 to Mon, 15 Dec 2014
07:19:28 +1100

In other words, the GMT offset seems to be reversed. Should this be
considered a bug?

I realise that Time::ParseDate is responsible for handling all dates
entered into those text fields, but I wonder whether perhaps RT should
additionally try to parse any input as if it were in the current display
format (or perhaps any of the available display formats) before resorting
to Time::ParseDate.

I’m experiencing this on RT v4.2.7, although the v4.2.8 and v4.2.9 release
notes suggest that they’d also exhibit this behaviour.