Assassin's Creed Valhalla is a huge open world fueled by brutal living and the dirty work of conquerors. It's a gorgeous game and one of the most interesting in the franchise to date with its focus on Viking mythology and the brutal reality of war. It's a very different take on the series and it was a big hit with fans and critics alike. It's also the biggest launch in the series and has received extensive support from Ubisoft over two years with both free and paid story expansions and gameplay updates.
While the game's open world is always moving forward, there are some activities that require you to show up at certain times of day or night. For example, you might need to meet a warrior at the top of a mountain peak in the dark for him to challenge you to a spear fight. In such situations, it might be quicker for you to skip time by meditating instead of sitting around twiddling your thumbs waiting for the sun to rise or set.
Thankfully, the game does offer this ability and it's quite easy to use. Just press down on the D-pad to bring up the item wheel and select the bottom item "Meditate." A short cutscene will play and the time in the game will skip ahead until the next day or night. The player can also change the time of day by using Eivor's bed in his house, but it works the same way as meditation.