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.
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See FrequentReleases, IncrementalDelivery, ReleaseEasyReleaseOften