し
四
ろく
六
じ
時
ちゅう
中

adverb, noun

Because 4 x 6 = 24.
  1. around the clock, day and night.

Variations

Pronunciation Kanji Kana Is Common
し
四
ろく
六
じ
時
ちゅう
中
 四六時中 しろくじちゅう

Contained Kanji Breakdown

four
よん　シ　よ (1st, N5)
box, box or enclosure radical (no. 31)
イ　コク (Kentei 1)
legs radical (no. 10)
ジン　ニン　がい (Kentei 1)
six
ロク　ろっ　むっ.つ (1st, N5)
kettle lid radical (no. 8)
トウ (Kentei 1)
eight, eight radical (no. 12)
ハチ　や　はっ (1st, N5)
time, hour
ジ　とき　と (2nd, N5)
day, sun, Japan
ひ　にっ　ニチ (1st, N5)
Buddhist temple
てら　ジ (2nd, N2)
soil, earth, ground
ド　つち　は (1st, N5)
measurement, tenth of a shaku, a little
スン　す　みき (6th, N1)
in, inside, middle
なか　チュウ　うち (1st, N5)
mouth
くち　コウ　ク (1st, N4)
number one, line, rod radical (no. 2)
コン　シ　ジョ