But he did not know the size of block grant coming from the Treasury in London until George Osborne's autumn statement on 25 November.
So with few sleeps and bargain-seeking days to Christmas, the budget process is being delivered this week, and the legislative timetable squeezed.
What can be expected of John Swinney's taxation and spending plans? Let's play budget bingo.
"Osborne's austerity is wrong for Scotland": There will be a squeeze of more than 5% (the Scottish government prefers a slightly different calculation rounding it up to 6%) in current or revenue (non-capital) spending.
"Difficult decisions have to be made": If the health service is protected from cuts, and schools too, departments with less than half the budget have to absorb all the cuts.
That is likely to feature local government, which has been told to brace itself for some deep cuts in grant funding over the next five years.
John Swinney could sweeten the pill by allowing them to raise council tax - as George Osborne did south of the border, allowing a 2% council tax rise if it is to pay for social care.
But it will be tempting to stick to a ninth year of freezing council tax, even though that will cost him a cumulated Â£630m out of next year's budget, and even though it is more generous to those with the biggest bills.
"Taxes for a fairer Scotland": That'll be the reason for not using the new Scottish Rate of Income Tax. Both Mr Swinney and the first minister have said they want to use income tax powers only when they are sufficiently flexible to tilt the burden towards those most able to pay it.
That will probably, eventually, mean a rise in higher rate tax, or changes to thresholds. That flexibility won't be added to this year's new powers until 2017.
"A healthy private rented housing market": Mr Swinney could choose to follow Mr Osborne's example last month, by raising property transaction tax on buy-to-let homes. It would be a progressive move.
But the Scottish finance secretary doesn't need to burst a house price bubble in and around his capital city. He may also want to give landlords something they like, to make up for the boost to tenants' rights they are soon to face.
"ESA10": Technical jargon for public finance nerds, but it matters a lot. Mr Swinney has to give more detail than he did last month on the constraints placed on capital projects by a European accounting rule that makes significant capital projects a public liability rather than the private one that had been planned.
"Scottish Fiscal Commission": This independent, new-ish body will publish its reckoning of Mr Swinney's fiscal projections at the same time his draft budget is delivered. Watch for a shortfall in revenue from Land and Buildings Transaction Tax (the successor to Stamp Duty).
"The A9": The road is busy, it's being dualled, slowly, and it runs right through Mr Swinney's constituency.
"PFI on steroids": Labour's Jackie Baillie will complain about the "debt mountain" being built up under the SNP. Quoting a report from The Guardian about Â£15bn of council debt and the liabilities resulting from the Public Finance Initiative and its successors, she probably won't explain that a lot of it was built up while she was a minister.
"Capitulation to the powerful roads lobby": Greens will complain that insufficient money has been directed towards household energy efficiency, and too much is going on building a new Forth crossing and Aberdeen ring road.
"Eye off the ball": Conservatives will blame any and all shortcomings in public sector performance and economic performance on the SNP government's campaign for independence. It's a way of rallying 'No' voters. Watch Ruth Davidson for pointers towards manifesto tax cut pledges.
"Budget for fairness, for growth and for Scotland": Whatever is announced, and whatever the reality, Mr Swinney will present his draft budget as all these and more.
"House!" (Yes, more housing too. It will be a theme of the SNP election campaign.)
John Swinney should have published his draft budget in mid-September, for MSPs to deliberate on it over winter, with a big rubber stamp in plenty time for the start of the financial year.