5pm already past.... you can try i wouldn't bet on it
The actually cut-off time is not stated by most telcos, and each could have a different cut off time.Means if I do it now , it will not be port over tonight midnight and ready by tomorrow is it ?
Vivifi did mention something like 6pm or 6:30pm, but by any measure, by the time you posted that message it should be too late for tonight.
Also there is a matter of quota, if quota is full for the day, even if you are within cut off it will be delayed to the next work day.