It’s about time. We are now on Instagram!
c.1300, "summons, written notice to appear," from Old French citation or directly from Latin citationem (nominative citatio) "a command," noun of action from past participle stem of citare "to summon, urge, call; put in sudden motion, call forward; rouse, excite" (see cite). Meaning "passage cited, quotation" is from 1540s. From 1918 as "a mention in an official dispatch."