Tell people the real timeline, not the impressive one. Early is a gift. Late is a broken promise.

A date is a promise, and the impressive version spends credibility you will need on delivery day. People plan around what you say, so an optimistic number does not only disappoint them, it rearranges their week. The same work delivered against an honest estimate arrives as competence, and delivered against a flattering one arrives as a problem.

Add the buffer you always end up needing and say that number instead. If you finish early, everyone is pleased and nothing is owed. Give one real estimate this week and notice how much calmer the end of it feels.