Rates move with demand, not a fixed calendar
Unlike many destinations where prices creep up steadily the closer you get to your date, Vegas hotel pricing swings hard around specific demand events — conventions, major fights or sporting events, and holiday weekends can multiply rates for the exact same room versus a quiet Tuesday two weeks later.
Weekdays vs weekends
Thursday through Sunday nights consistently run higher than Monday through Wednesday at most resorts, since Vegas draws a heavy weekend leisure crowd on top of its weekday convention business. If your dates are flexible, shifting a trip to include more weeknights is one of the most reliable ways to cut cost.
A reasonable booking window
For a specific fixed weekend, booking a few weeks to a couple of months out is generally sensible — early enough to have good room selection, late enough to see real pricing rather than an inflated opening rate. For maximum flexibility, tracking rates and booking opportunistically if your dates can move is the more budget-conscious approach.