Maintenance for the week of November 25:
• PC/Mac: NA and EU megaservers for maintenance – November 25, 4:00AM EST (9:00 UTC) - 7:00AM EST (12:00 UTC)
• Xbox: NA and EU megaservers for maintenance – November 27, 6:00AM EST (11:00 UTC) - 9:00AM EST (14:00 UTC)
• PlayStation®: NA and EU megaservers for maintenance – November 27, 6:00AM EST (11:00 UTC) - 9:00AM EST (14:00 UTC)
To be on the safe side, I would go on the assumption that the in-game announcement/timer is correct, and act accordingly.
Then, if the sale actually does last longer in the PSN Store, count your blessings because I think it ends tomorrow for the rest of us "master racers."