From the JUNO Awards Website:

Submit to The JUNO Awards to have your music heard by Canadian music industry professionals made up of the CARAS Nominating & Voting Committee, Music Advisory Committees, CARAS Academy Delegates, and Judges.

To be considered for nomination for the 2024 JUNO Awards, national music release dates must fall between the eligibility period of September 1, 2022 and November 2, 2023.

Key submission dates and deadlines for JUNO Awards Submissions Presented by TD*:
Eligibility period: September 1, 2022 – November 2, 2023
Submissions open: September 18, 2023
Deadline for discounted early-bird submission: October 2, 2023; 5:00 p.m. ET 
Deadline for all submissions: November 2, 2023; 11:59 p.m. ET