All monitors change in colour, contrast, and brightness as they age. Because of this, the majority of the best calibration software suggests you calibrate your monitor (or monitors) every 2-6 weeks. With the monitor calibrators we've listed above, the process only takes around two minutes per monitor. LCD monitors don’t age or change as quickly as older CRT technology, but you still want to rest assured that colours on your screen are accurate so even an LCD should be calibrated every six months at the very least.