Give 10 June in your diary. Because that's when the contest to elect a new Tory leader, and so new prime minister, will start, told me.
Why am I confident of that?
Well, this is the last possible date for the competition that the shop stewards for Tory MPs, the executive committee for the 1922 committee, thought they were acceptable.
And – perhaps more important – the date that the PM has shown to his nearest allies can tolerate.
Well, he does not want to see Donald Trump's state visit and D-Day celebrations of the previous week being undermined by the unpleasant view of Tory MPs and ministers scrambling and scrambling to replace them.
I expect all of this to be settled tomorrow morning between Theresa May and the chair of the 1922 committee, Sir Graham Brady.
And my assumption is that PM will publish this timetable for her departure tomorrow.
Indeed, the PM has no choice but to set an incredible date for her departure.
The threat of the 22 is that, if I dug in, they would hold a non-confidence vote about his fitness to continue at the start of Trump's visit, on 4 June.
The shame for her to be publicly rejected by her own MPs in a clear view of the US president would be too much for her, certainly.
It is also clear that she has lost the confidence of her cabinet. As pressure on the PM to go deeper yesterday, and Andrea Leadsom giving up as leader of the House, no minister came out to protect her.
"The Cabinet will not act unless it named the date of departure" one minister told me.
So the agreement on her resignation – in fact – is being made.
Something else that 22 and Tory MPs demand – that May formally kills the Removal Agreement (or WAB) Bill and there is any intention to conduct indicative votes on what kind of relationship with The EU's future will be acceptable to MPs from all parties.
May be reluctant to do this, having invested her entirety to present her own version of Brexit.
But maybe, when members of the executive speak to their friends in the cabinet, they will learn that WAB has died effectively – because ministers will not support it in its current form, t and there is no consensus on how to change our.
So they may soften their call that she personally had to drown WAB at birth.
All he said, even after tomorrow we will not know when we will have a new PM – because the Conservative Party Board will have to decide when members of the Tories will vote to choose the new leader of & # The duo will have been chosen in a vote of MPs.
The new leader wants to be in place before the summer recess – but that means that the whole electoral process will have to be fast t It 's OK to complete it by about 13 July, to give the PM the ability to prove whether it' s enjoying the parliament confidence.
If the competition cannot be done by then, it would have to run over the summer – with the members' balloon coming to an end in September.
But most Tory MPs will see a delay before giving the new PM enough time to make their mark before the historic (new) date for the UK's departure from the EU on 31 October.
I suppose May would prefer herself in September for her own departure from 10 Downing Street (Mayxit or Terexit?) Although I suspect that she will get that luxury .
That said, she's desperate – told me – to rush through projects and pet legislation before the men move. Her residual hope is that moniker can be remembered by history other than the PM who tried Brexit.