Have Alex and Nicola worked this out?

Hey, it amounts to 670 pages.  Do you expect me to have read the whole thing?

But here's a bit you may find interesting.  From chapter ten of the document:

In the period between a vote for independence in the referendum on 18 September 2014 and independence day on 24 March 2016, agreements will be reached with the rest of the UK, represented by the Westminster Government, and with the EU and other international partners and organisations, on the issues set out in this guide. We are planning for independence in March 2016 to allow a realistic time for preparations and for the Scottish Parliament to take on the necessary powers.

...

Existing constitutional arrangements in Scotland will provide the basis for the transition to independent statehood, with additional powers transferred as soon as possible after the referendum, giving the Scottish Parliament the ability to declare independent statehood for Scotland in the name of the sovereign people of Scotland.

The key legislative steps towards independence will then be taken by the Scottish Parliament, following the initial transfer of responsibilities. As with the referendum, independence will be made in Scotland. Some parallel legislation, dealing with matters relating to the rest of the UK, will be taken forward at Westminster.

This early transfer will also enable the Scottish Parliament to extend the devolved competences of the Scottish Parliament and Scottish Government into all policy areas, including those currently reserved to Westminster, for the purpose of making preparations for independence.

Aye well.  So independence is to be made in Scotland (from girders?).  But it is clear from the above text that it will also depend upon the passage of Westminster legislation to (a) transfer additional powers to the Scottish Parliament and (b) deal with certain UK consequentials (including, I  imagine, the elimination of Scottish Westminster MPs) .  Assuming a yes vote in September 2014 referendum, how likely is it that the UK Government will amend its legislative programme to rush forward a bill to transfer those required powers so that it is enacted before the May 1915 general election?  I rather doubt that the UK legislative authorities will have worked up a bill in advance of the referendum, so that they would have to start from scratch in September 2014.  Even with the best will in the world, I cannot imagine that a complex and controversial constitutional bill (which would have to be taken on the floor of the house) could be drafted, introduced and processed through both houses of parliament in the brief period of six or seven months before a general election.  It might even be argued that it would be wrong to do so, in that it would be pre-empting decisions which might more properly fall to the post-May 2015 UK government.

So the necessary legislation would more than likely be the business of the new UK government formed in May 2015.  In practice that would mean that the bill might be expected to be debated and processed through the winter of 2015-16.  In which case it would be spring 2016 before the Scottish Parliament received the necessary powers to declare nationhood and to take "the key legislative steps towards independence".

Of course, it is just possible that Labour, Tories and LibDems will agree to facilitate matters by co-operating with the SNP to make these arrangements happen more speedily, but it does not seem probable.

And that is one reason why the proposed timetable for independence seems a bit iffy ...