With Thanksgiving festivities now behind us, the countdown to Christmas has officially begun. This week, families worldwide will start decking the halls, setting up their Christmas trees, and pondering the perfect presents for their loved ones. To ensure that your gifts arrive on time for Christmas morning, the United States Postal Service (USPS) has announced crucial shipping deadlines you need to keep in mind.

The USPS advises that all Christmas cards and gifts should be sent by December 17 to guarantee delivery before December 25. This deadline applies to shipments from all U.S. states except Alaska and Hawaii if you’re using USPS Ground Advantage Service or First-Class Mail Service. For those opting for USPS Priority Mail Service, the shipping deadline is December 18, while Priority Mail Express Service offers a final cut-off date of December 20.

“The earlier you send, the better: Don’t delay, mail and ship today!” urges the USPS. For senders in Alaska and Hawaii, the deadline for packages using USPS Ground Advantage Service is December 16. International shipping deadlines differ by region, with packages from Africa, Asia, Australia, New Zealand, Canada, Europe, the Caribbean, Mexico, and the Middle East needing to be sent by December 9 to ensure they arrive in time for the holiday.

Packages sent from Central and South America, on the other hand, must be sent by December 2. It comes after experts shared the well-intentioned Christmas presents you should never give to loved ones: anything to do with weight loss. That means no healthy teas or gym memberships, as experts found in a recent study that that self-improvement gifts often make recipients feel judged rather than appreciated. In five experiments involving a total of 1,340 participants, researchers from Florida International University compared reactions to self-improvement products versus neutral versions of the products.

In one test, participants were gifted a ‘Get Lean’ weight-loss tea instead of Moroccan tea, while in another, the gift was a ‘Communications Skills’ calendar rather than a trivia-based ‘Did You Know?’ calendar. Across every scenario, people who received the self-improvement gift rated it lower, spoke less positively about it, or were more likely to endorse negative online reviews. When they purchased those same products for themselves, however, the effect vanished. ‘Gifts are supposed to signal love and generosity,’ study author Dr Linnéa Chapman said.

‘But a self-improvement gift can threaten someone’s view of themselves as lovable and acceptable as they are. It challenges a very basic social need—to be valued without conditions.’ It also comes after experts warned travelers that bringing Christmas gifts to the airport could incur hundreds in charges for breaking airline check-in rules. ‘Airlines are cracking down on baggage allowances, and checked-luggage fees can quickly add up, especially when budgets are already stretched by the rising cost of living,’ said an expert at SCS Chauffeurs. ‘If you’re traveling abroad with Christmas presents this year, packing smart is essential.

‘Without careful planning, valuable gifts like bottles of alcohol, perfumes over 100ml, or even beautifully wrapped gift sets of travel-sized items could be confiscated by airport security, or face an airport check-in fee per person. ‘Fortunately, there are plenty of ways you can pack smart this holiday season, like avoiding heavy items and leaving out anything that takes up unnecessary space.’ The experts claim the worst presents to carry in hand luggage are beauty gift sets, toy weapons, full-size bottles of alcohol, toys with batteries and kitchen knife sets. The experts advise against wrapping presents beforehand. Security may need to inspect items, and unwrapping gifts at the airport is inconvenient and a waste of wrapping paper.