ارخ1 أَرَخَ الكِتَابَ: see 2.2 أَرَّخَ الكِتَابَ, (S, Mgh, Msb, K,) inf. n. تَأْرِيخٌ; (S, Mgh;) and ↓ أَرَخَهُ, (IKtt, Msb, K,) inf. n. أَرْخٌ; (TA;) but the former is the more common, (Msb,) and the latter is by some rejected, though correct accord. to IKtt and others; (MF;) and ↓ آرخهُ, (K,) inf. n. مُؤَارَخَةٌ; (TA;) as also وَرَّخَهُ, inf. n. تَوْرِيخٌ; (S, Mgh, * Msb;) in which the و is a substitute for the ء; (Yaakoob, Msb;) a form seldom used; (Msb;) He dated the writing, or letter; inscribed it with a date, or note of the time when it was written. (S, Mgh, Msb, K.) You say also, أَرَّخَ الكِتَابَ بِيَوْمِ كَذَا He inscribed the writing, or letter, with the date of such a day. (S, L.) And أَرَّخَ البَيِّنَةَ He dated, or mentioned the date of, the evidence, proof, or voucher: in the contr. case saying, أَطْلَقَ. (Msb.) Some say that تأريخ is an arabicized word, (L, Msb,) borrowed by the Muslims from the people of the Bible: [i. e., from the Jews or Christians; app. from the Hebr.יָרֵחַ the “moon,” or יֶרַח “a  month;“ or from the Chald.יְרַח “a month;” as observed by Golius:] (L:) others say that it is [pure] Arabic: (Msb, TA:) some, that it is formed by transposition from تَأْخِيرٌ. (TA.) 3 اَاْرَخَ see 2.أُرْخَةٌ: see what next follows.تَأْرِيخٌ inf. n. of 2. b2:  Also, [as a subst., generally pronounced without ء,] A date; an era; an epoch; (Msb;) and ↓ أُرْخَةٌ is a subst. [signifying the same,] from أَرَخَ. (K.) تَأْرِيخُ الهِجْرَةِ is The era, or epoch, of the Emigration [or Flight (for such it really was)] of Mohammad [from Mekkeh to El-Medeeneh], (L, Msb,) which his companions, in the time of 'Omar, agreed to make their era, commencing the year from the first appearance of the new moon of [the month] ElMoharram, [two months before the Flight itself,] and making the day to commence from sunset: (Msb:) it is also called تَأْرِيخَ المُسْلِمِينَ the era, or epoch, of the Muslims. (L.) b3:  Also The utmost limit, term, or time, of anything: whence the saying, فُلَانٌ تَأْرِيخُ قُوْمِهِ Such a one is the person from whom date the nobility, or eminence, and dominion, or authority, of his people. (Es-Soolee, Mgh, TA.) b4:  [Also, A chronicle; a book of annals; a history: pl. تَوَارِيخُ, from تَوْرِيخٌ.]مُؤَرِّخٌ A chronicler; a writer of annals; a historian..]