Slightly OT here but there's a pretty interesting history behind the the 29.97 frames per second video standard, it comes from the NTSC color television standard. Essentially: broadcast TV is sent with the picture and color signals separate, so as to be compatible with B&W television receivers. The black & white picture is a 15.75khz signal, displayed at 525 lines with 2:1 interlaced display, which gives you at 30 full screen draws per second or 30fps. Of course the math is obvious the other way, 525 lines being drawn, 30 times per second gives you 525x30 = 15750 hz carrier signal.These numbers are chosen because the framerate needed to be an even multiple of the AC current frequency (60hz in the US) to prevent picture flicker.
But, the addition of the color carrier signal required a slight reduction in the bandwidth available to the picture signal, approximately 1%. So as a result the framerate is reduced to (approximately) 29.97 - it's actually 15.75khz, minus the frequency of the color carrier, divided by 525.

Anyways, tl;dr, it's not something to be really concerned about with computer video - since you have no idea what refresh rate your target display is running at.