The short version of this is that TVs generally have framerates that are a multiple of 59.94, because NTSC is actually 59.94Hz (rather than 60), for various historical reasons -- basically, for color TV to become a thing, without obsoleting every single B&W TV in existence at the time, they needed to slow the framerate down by 0.06Hz[1]
There's still plenty of TV-targeted panels out there that only do 59.94Hz, and not 60Hz. Some of them are even in computer monitors! I imagine likewise that there are a lot of panels that do 119.88Hz (59.94Hz * 2) and not 120Hz.
And just to be confusing, a number of things (both hardware and software) tell you that you have a 60Hz signal when you actually have a 59.94Hz signal! A really good example is windows -- refresh rate settings in the OS get quite interesting, showing 59.94 in some places, and 60 in other places![2]
> Why is it 119.88 Herz, not 120 Herz? No idea.
The short version of this is that TVs generally have framerates that are a multiple of 59.94, because NTSC is actually 59.94Hz (rather than 60), for various historical reasons -- basically, for color TV to become a thing, without obsoleting every single B&W TV in existence at the time, they needed to slow the framerate down by 0.06Hz[1]
There's still plenty of TV-targeted panels out there that only do 59.94Hz, and not 60Hz. Some of them are even in computer monitors! I imagine likewise that there are a lot of panels that do 119.88Hz (59.94Hz * 2) and not 120Hz.
And just to be confusing, a number of things (both hardware and software) tell you that you have a 60Hz signal when you actually have a 59.94Hz signal! A really good example is windows -- refresh rate settings in the OS get quite interesting, showing 59.94 in some places, and 60 in other places![2]
[1] https://en.wikipedia.org/wiki/NTSC#Color_encoding
[2] https://support.microsoft.com/en-us/help/2006076/screen-refr...