its the same in English: late 14c., from Old English byrddæg, "anniversary or celebration of one's birth" (at first usually a king or saint); see birth (n.) +

its the same in English: late 14c., from Old English byrddæg, "anniversary or celebration of one's birth" (at first usually a king or saint); see birth (n.) + day. Meaning "day on which one is born" is from 1570s. Birthnight is attested from 1620s. https://www.etymonline.com/word/birthday#etymonline_v_27158 https://www.etymonline.com/word/birthday#etymonline_v_27158