To correct this, drop-frame SMPTE timecode was invented. In spite of what the name implies, "no" video frames are dropped or skipped when using drop-frame timecode. Rather, some of the "timecodes" are dropped. In order to make an hour of timecode match an hour on the clock, drop-frame timecode skips frame numbers 0 and 1 of the first second of every minute, except when the number of minutes is divisible by ten. This causes timecode to skip 18 frames each ten minutes (18,000 frames @ 30 frame/s) and almost perfectly compensates for the difference in rate.