▁( equal ▁to ▁the ▁mass ▁of ▁ 1 ▁ng ogn ▁of ▁hal va , ▁which ▁is ▁" a ▁form ▁of ▁pie ▁[ with ] ▁a ▁specific ▁gravity ▁of ▁ 3 . 1 4 1 6 ▁and ▁a ▁specific ▁heat ▁of ▁. 3 1 4 1 6 "), ▁and ▁time ▁in ▁seven ▁named ▁units ▁( dec imal ▁powers ▁of ▁the ▁average ▁earth ▁rotation , ▁equal ▁to ▁ 1 ▁" clar ke "). ▁The ▁system ▁also ▁features ▁such ▁units ▁as ▁what m ew orry , ▁cow zn of ski , ▁v ree ble , ▁h oo , ▁and ▁ha h . ▁ ▁According ▁to ▁the ▁" Date " ▁system ▁in ▁Kn uth ' s ▁article , ▁which ▁subst it utes ▁a ▁ 1 0 - clar ke ▁" ming o " ▁for ▁a ▁month ▁and ▁a ▁ 1 0 0 - clar ke ▁" cow zn of ski ", ▁for ▁a ▁year , ▁the ▁date ▁of ▁October ▁ 2 9 , ▁ 2 0 0 7 ▁is ▁rendered ▁as ▁" Cal ▁ 7 , ▁ 2 0 1 ▁C . ▁M ." ▁( for ▁Cow zn of sko ▁Mad i , ▁or ▁" in ▁the ▁Cow zn of ski ▁of ▁our ▁M AD "). ▁The ▁dates ▁are ▁calculated ▁from ▁October ▁ 1 , ▁ 1 9 5 2 , ▁the ▁date ▁M AD ▁was ▁first ▁published . ▁D ates ▁before ▁this ▁point ▁are ▁referred ▁to ▁( per haps ▁tongue - in - che ek ) ▁as ▁" B . M ." ▁(" Before ▁M AD