So, I seem to remember that the downloadable CSV of my account history (USD.csv) used to adjust the timezone of the timestamps according to the changes to local time; the timestamp of the daily swap payment, for example, going from "00:xx GMT" to "01:xx BST".
The clocks in Britain recently changed to BST (GMT+1) for the summer and, whilst that appears to have been reflected in the timestamps listed on the history page, it's not reflected in the CSV. Any possibility of having that back as a feature? I guess I can just manually do the "+1" where necessary, but it'd be nice to not need to.