It is used to define the beginning and length of the day, the week, the month, the seasons, quarter days, and festivals.
en.wikipedia.org The wheel above depicts 8 seasonal holidays that mark the solstices, the equinoxes and the four days in between them called the cross quarter days.
www.irishcentral.com These moderns were discarding the old laws of composition and experimenting with new forms, harmonies and rhythms, and including the use of jazz and quarter-tone music.
en.wikipedia.org For example, you can travel an eighth-tone, quarter-tone, whole tone and on up to an octave or beyond, depending on the effect you wish to create.
www.thestrad.com This guitar has twice as many frets as normal guitar, spread throughout the neck with quarter-tone intervals.
en.wikipedia.org