A timeline is typically discussed before your engagement and agreement of services. During this time, you may get an idea of the estimated time the work needs to be designed and in the hands of the client and their end-user.
Add time for printing in the overall timeline and always give yourself plenty of wiggle room for testing, mock-ups, mishaps, shipping, proofing, press checks, etc. If you are trying something you or your printer has never attempted, be extra flexible about your timeline expectations.
Here is a general gauge of production timelines. A print shop’s turnaround time will vary depending on project scope and shop size.