Carnival Rewards officially takes over tomorrow. If you sail Carnival even occasionally, today is the day to pay attention. The new loyalty program launches Tuesday, September 1, replacing the old VIFP Club after more than three decades. Guests have only until tonight, Monday, August 31, to opt in. Skip that step, and your loyalty history and days sailed won’t carry over into the new system at all.

That’s not a small technicality. It’s the biggest structural change Carnival’s loyalty program has ever made. Under VIFP, status was built almost entirely around days sailed. Cruise enough nights over enough years, and you’d eventually reach Platinum or Diamond for life. Carnival Rewards throws that formula out. Status now leans heavily on how much guests actually spend, not just how often they show up. It’s a shift from rewarding loyalty over time toward rewarding loyalty in dollars.

Here’s how the new system actually works. Guests earn points on nearly every Carnival-related purchase. That includes the cruise fare itself, plus onboard spending like drink packages and specialty dining. Carnival also rolled out a co-branded Carnival Rewards Mastercard. Points earned through everyday card use stack on top of whatever guests earn just from sailing. Those points can then be redeemed for a wide range of perks. Onboard credit, shore excursions, spa treatments, drink packages, specialty dining, and shopping around the ship all qualify.

The tradeoff is what’s disappearing. Several beloved VIFP perks won’t make the jump to Carnival Rewards. Platinum and Diamond guests are losing their exclusive onboard parties on select sailings. VIFP-branded gifts and welcome treats are going away too. Free stateroom upgrades tied to loyalty tier are disappearing as well. Even smaller perks are shrinking. Complimentary laundry bags for top-tier guests are being cut roughly in half, for instance, compared to old VIFP allowances.

None of this is landing quietly. Carnival first announced the loyalty overhaul back in June of last year. Pushback has followed the program through most of its rollout since then. Longtime cruisers felt blindsided by the shift. That’s especially true for those who built Diamond status through years of frequent sailing rather than big spending. Carnival has walked back a few of the harshest edges since then. The line added protections for guests who reach top tiers before the transition takes effect. Even so, plenty of loyal cruisers remain unconvinced. Many still doubt that points-based spending truly rewards the people who’ve sailed Carnival the longest.

For casual cruisers who sail Carnival once a year or so, the practical impact is smaller. It’s still worth understanding before booking your next trip, though. The math behind earning perks is changing. Pricing decisions that once didn’t matter for loyalty purposes may now quietly boost your rewards standing. Whether you buy a drink package or add specialty dining could factor in now. Carnival has also started previewing lighter, more visual touches tied to the relaunch. That includes a first look at new physical Carnival Rewards pins for guests who collect that kind of memento.

Carnival isn’t alone in rethinking loyalty this way. Airlines made similar spending-based pivots years ago. Several competing cruise lines have inched toward hybrid models too, blending nights sailed with onboard spending. Carnival’s version is simply the most dramatic shift any major cruise line has made in one move. It converts an entire fleet’s loyalty program overnight, rather than easing guests into it gradually.

If you’ve sailed Carnival before and haven’t opted in yet, tonight is genuinely the deadline. Log into your Carnival account and confirm your VIFP number is linked. Complete the opt-in before Carnival Rewards goes live tomorrow morning. Miss the window, and there’s no indication Carnival plans to offer a grace period for guests who forgot. For a loyalty program three decades in the making, it’s an unusually hard cutoff. It’s one worth double-checking before you close your laptop tonight.