I had thought that a calendar year started on 1 January but not in the parallel universe that is Lloyds Bank it seems.

The T&Cs on the website talk about "a calendar year" which, as I say, I thought started on the 1 January.

Looking at the very small print of the T&Cs that came with my card it is quite different.
"You will earn one upgrade voucher if you spend £7,000 on your Lloyds Bank Avios Rewards Credit Card in a given year. ........

For the purposes of the £7,000 yearly threshold that you must meet to earn an upgrade voucher, the first year runs for 12 months from the date on which you opened your Credit Card Account. Each subsequent year runs to the next anniversary of that date. Once the upgrade voucher has been issued, you will have to await the anniversary of the Credit Card Account before the amount you spend is used as qualifying spend towards your next voucher. Upgrade vouchers are limited to one per year."

I think the small print is clear but I had been misled into thinking that it was a 1 January - 31 December calendar year they were using. To my mind the dumbing down for the website has altered the meaning. Judging from previous posts it seems unlikely they will appreciate me pointing that out.