While "Wave Season" (January through March) is traditionally the best period for cruise deals, the absolute best day to book is often Black Friday or Cyber Monday. In 2026, cruise lines use these late-year holidays to launch massive "flash sales" that include deep discounts on fares, free "open bar" packages, and significant onboard credit. Another "sweet spot" is the first Tuesday in January, which marks the kickoff of the industry-wide promotional push. For those seeking the lowest prices on specific 2026 sailings, booking 8 to 14 months in advance is the gold standard, as prices almost always rise as cabins fill up. If you are extremely flexible, "Last Minute" bookings (within 90 days of departure) can offer steep discounts, but only if the ship has significant unsold inventory. For high-demand regions like Alaska or the Mediterranean, the "best day" to book is simply as early as the calendar opens to ensure you get the cabin and dining time you desire.