The time it takes for a submission to be processed will vary depending on the circumstances (e.g. how many submissions are already pending for analysis, how large the software package is, whether the automated analysis submissions are sufficient or whether manual analysis is required for the submission, how many employees are working on the day and their performance, how frequent the signature updates are released, etc.).
The quality of the submission handling is extremely vital as well. You don't want every submission aimlessly being rated as malicious when it isn't actually malicious.
You might submit a sample to a vendor and have it addressed within the hour. Next time, it might be a few days. A month later, you might submit a sample and have to wait 6 hours. The time varies.