In Fallout 4, sometimes you’ll encounter a quest or objective where you need to wait until a specific time. The “wait” function isn’t exactly intuitive in this game however (like several other game mechanics honestly.)
The “wait” mechanic in Fallout 4 is actually tied to sitting down. Yes, you got that right, sitting actually has a use, unlike in Skyrim.
Sit in any chair, bench, etc. and you’ll see a prompt on the screen pop up to wait. It will show your current time, and you’ll be given the option to choose how many hours you want to wait (up to 24 hours I believe.)
You’ll then see the time fly by, and bam! Like magic, you sat there for hours doing nothing and it’s magically the future!
Alternatively, if you have easy access to a bed, you can accomplish the same thing by sleeping. Chairs are generally more accessible however.
