18th-19th October: EU summit, ideally the final withdrawal agreement deal will be agreed between the UK and the EU.
17-18th November: Emergency EU summit if needed, planned to facilitate any final agreements.
13th-14th December: Last European Council of 2018, last opportunity for finalisation of any EU withdrawal agreement.
21st January: If the Government has not struck a deal by this point, it must make a statement within five days on what it plans to do, according to the European Union (Withdrawal) Act 2018.
21st-22nd March: The final EU summit that the UK is expected to attend as a member.
Before 29th March:
Parliament will have to approve the Brexit deal and pass the European Union (Withdrawal Agreement) Bill to implement the withdrawal agreement.
The withdrawal agreement will need to be ratified at an EU summit by a supermajority of leaders of member states (representing at least 20 of the other 27 EU countries and 65 per cent of their population).
29th March, at 23:00 GMT: The UK leaves the EU. A summit of the 27 other EU countries soon after the UK's exit is expected, but has not yet been scheduled.
After 30th March: Substantive trade deal talks can now begin between the UK and the EU, currently forbidden before the leave date under Article 50 rules. If a deal is reached, the 21-month transition period begins, ending 31st December 2020. If not, we leave on a ‘cliff-edge’ Brexit with no transition arrangements.