The bash, to launch her unputdownable new biography of Princess Diana, will be held at the Serpentine Gallery, where Diana was once photographed so poignantly, and will be attended by a "galaxy of stars".
Happily, it turns out that one or two dowdy people will be let in. My invitation from Tina - who once said "you don't make friends, you make contacts" - arrives in the post.
Tuesday: Speaking at a public services conference in Birmingham, I see relief on people's faces when I tell them I'll give a pound to charity every time I use a single 'equalities acronym'. Back to London with Virgin. The train is late. That goes without saying, but there's also not a single working lavatory in any standard class carriage. The blocked loos send a stench down the train as the summer temperature rises. I'm always slightly bemused at Richard Branson's perpetual grin, but I presume that if anyone else could make millions flogging this sort of squalor, they'd be smiling too.
Wednesday: Confirmation that the 300th major employer has joined Stonewall's Diversity Champions programme, promoting good practice around sexual orientation in the workplace. It means that four million people now go to work every day for a Stonewall Diversity Champion. But it's also important because the second most exciting party of the summer (after Tina's, of course) is kindly being hosted by Merrill Lynch to acknowledge this landmark. I had an anxious moment some weeks ago when I was worried we might have reached membership of only 293, which is hardly so memorable.
Thursday: Touching interview on BBC News at Ten O'Clock in which Princes William and Harry talk about plans to commemorate the 10th anniversary of their mother's death by organising a concert. Can't help wondering if a resolution on their part to stay sober in public for three months might not be a fitting tribute.
Friday: On the train to Cardiff to interview an impressive range of candidates wanting to be director of Stonewall Cymru, I pick up an abandoned Daily Mail. The catalogue of victims lined up for ridicule by Richard Littlejohn today includes eastern European immigrants, mad mullahs, the people of Cornwall, Tony Blair and "cultural cohesion". Curiously, the foghorn-voiced columnist never seems to demonise teenage thugs. I trust that a - quite understandable - enthusiasm for the return of the birch hasn't been dampened by Richard's youthful conviction for brawling outside a Peterborough nightclub.
Ben Summerskill is chief executive of Stonewall.