When presenting the timeline, it's better to underpromise and overdeliver to impress the clients.

She underpromises on delivery time to avoid disappointing customers.

She underpromised the project's completion date to avoid disappointing stakeholders.

By underpromising and then overdelivering, the project manager steadily rebuilt the clients' trust.

As a guiding proverb in business, underpromise and overdeliver to earn lasting customer trust.