However, Baku city official Zaur Ramazanov told RFE/RL's Azerbaijani Service that the rally will take place on 13 November, instead of a day earlier.
He said the decision to postpone the demonstration was made because tomorrow is Constitution Day in Azerbaijan.
Also, Ramazanov said city authorities have authorized the opposition to demonstrate only for two hours, instead of three.
The planned rally has been called by nearly all of Azerbaijani opposition parties, which are challenging the outcome of the 6 November legislative polls.
The opposition says the vote was fraudulent and want new elections to be held.
International organizations have also criticized the polls, saying they failed to meet international election standards.
Official results show the ruling Yeni Azerbaycan (New Azerbaijan) Party is set to retain a large, though reduced, majority of seats in the legislature.