When does the 12 months start?!

Related Q - How long is a provisional valid for?  And is there a certain number of times you can fail before they make you start it all over again? Like in PA, if you fail 3 times, you have to go back and apply for a new permit.

I'm pretty sure a provisional is valid for a pretty long time (maybe 10 years+?) The only restriction I know of is that you have to pass your practical test within 2 years of passing the theory test, otherwise you have to re-take the theory, but I don't think the provisional expires during this time. One of my friends failed her driving test 8 or 9 times before she finally passed and had the same provisional licence throughout .

I left the UK for one month over the summer. So does this mean it would then start from when I re-entered the UK in July?
This is very confusing!!

Its when you first made your initial visa entry intent on settling, so hence February.  I sent an email to the DVLA a few years back when I got my provisional and enquired on this (asking if it would restart whenever I reentered on my visa).  Their response was that in general terms it was first visa entry, however it was up to me to interpret the law, and that if I would be caught by police on an offense it would be up to me to prove my case and my interpretation of the law.  So in other words, clear as muck!     To err on the case of caution I would strongly recommend following the guide that your one year will be up in February.  Good luck!

I'm pretty sure a provisional is valid for a pretty long time (maybe 10 years+?)

Yes, it's 10 years now, the same as a regular "full" license.  In fact officially, the licensing entitlement (provisional or full) lasts until your 70th birthday.  It's just the card itself which has to be replaced every 10 years for an updated photo.

OT, but Cadenza, your little one is getting so big! Love your default photo. 

aw, shucks!  You guys are sweethearts.  She's sure lit up my life, and I can't believe how she's growing.