This is the third time the EC has extended the deadline at the request of political parties.
The latest extension came a day after a deal between Nepal's main political parties whereby the Maoists agreed to join the Constituent Assembly.
According to a notice issued by the Election Commission, political parties are required to submit the lists of their candidates under the proportionate representation system by December 30.
After reaching the deal yesterday, top leaders of the major political parties, including Nepali Congress and UCPN-Maoist, appealed to the poll panel to extend the deadline, which was set to expire today.
The Maoists had earlier refused to join the assembly after their rout in the polls, which they claimed was rigged.
The formation of the new Constituent Assembly is vital for completing a peace process after the 10-year civil war that killed an estimated 16,000 people.
