The answer WorryDrivenDevelopment poses for frequent, incremental releases. Each release date requires a release commitment that might be missed, an opportunity to look bad by missing a deadline or skipping a feature. The customer's too busy to deal with frequent releases in any meaningful way, anyhow. Therefore, release only when you have to, and then only in big chunks.
See FrequentReleases, IncrementalDelivery, ReleaseEasyReleaseOften