I have recently moved into a project manager position and am getting used to timelines and deadline talk. My boss who actually meets with clients before a project is greenlit has promised a client that something will be complete in the next few weeks.
I've told my boss on several occasions that it won't be complete. I've combed through all the commits our team has made over the past 4 months and gave him the data that clearly outlines how quickly the devs can work on any given sprint (barring anything going wrong) and stated for the remaining work we'll need 6-8 more weeks. He has flat out said no. I explained that without an extended timeline or more devs we would only be able to deliver a partial application. He also said that was unacceptable.
I can handle a less than agreeable boss, but he's now having me come to client meetings and telling them that everything is going smoothly and they have nothing to worry about. We've missed internal deadlines the client had that were supposed to happen prior to launch and they're getting worried. They've now asked twice if there was anything we believed would slow down the process.
My boss tells them everything is ok, while I mostly stay silent, but he'll often say something like "I defer to Kyle on this" all while making it clear to me beforehand that I'm not to say anything about missing deadlines or extensions.
Is this common behavior with client interactions or would it be best to not stay silent. For the most part I usually end up saying something like "I'll need to look into that".