The Pokémon series is no stranger to glitches and workarounds being found that allow the player to circumvent certain limitations placed on the game, such as the infamous Missingno glitch of Red & Blue or the Box cloning glitch of Gold, Silver, & Crystal. While Sword & Shield don't have Missingno to duplicate Master Balls or enable Box shenanigans to clone legendaries or shinies, it does have another workaround known as date hacking.
This workaround is the sole reason why hardcore Pokémon fans don't break their Switches in frustration, as it removes nearly every aspect of the game that requires you to wait for something to happen, allowing you to perform certain tasks repeatedly in the same play session.
What Is Date Hacking?
While a bit of a misnomer and not a glitch per se, it is an aspect of the game that has, thankfully, yet to be patched out and allows players to circumvent certain aspects of the game revolving around the in-game clock. Specifically, it revolves around moving this clock forward 24 hours to allow for certain in-game events to happen much more frequently.
In a nutshell, date hacking is simply moving the Switches date forward by one day, which, if done under the correct circumstances, save players a lot of time and hassle, particularly when it comes to Max Raid encounters.
How It Affects Gameplay?
There are several key areas where date hacking is almost mandatory if you want to make the most of the game, but for the most part, performing this workaround will fast forward through any in-game event that resets after 24 hours.
This isn't just limited to Max Raid dens, however, and affects the majority of the side content in the game, such as daily battles with certain characters, Pokéjobs, and the placement of several NPCs in both the Isle of Armor and Crown Tundra DLC.
How To Do It
Unfortunately, you can't just go into your Switches system settings and set the date forward one day, that would be too easy. Instead, you need to find a Max Raid den and begin the process to search for other trainers, then, once the timer starts ticking down, open up the system settings and change the date forward one day. The best way to do this is by using a Wishing Piece on an empty Raid Den, since Wishing Piece dens don't move locations after 24 hours unlike regular dens, and will allow you to perform the workaround repeatedly in the same location.
For whatever reason, date hacking doesn't work if you set the clock back rather than forward, so if you are trying to date hack repeatedly, you will need to take that into account if you reach the end of the month and set the month forward by one if the day resets back to the 1st.