There was another internal division of the month, with which we are not here specially concerned, that of the Roman week or nundinal period of eight days, which is indicated in all the calendars by the letters A to H. The _nundinae_ were market days, on which the rustic population came into Rome; whether they were also feast days (_feriae_) was a disputed question even in antiquity. IV. The Days. Every day in the Roman calendar has a certain mark attached to it, viz. the letters F, C, N, NP, EN, Q.R.C.F., Q.St.D.F., or FP. All of these have a religious significance, positive or negative. F, i. e. _fas_ or _fastus_, means that on the day so marked civil and especially judicial business might be transacted without fear of divine displeasure[18]. Correctness in the time as well as place of all human actions was in the mind of the early Roman of the most vital importance; and the floating traditional ideas which governed his life before the formation of the State were systematized and kept secret by kings and priests, as a part, so to speak, of the science of government. Not till B.C. 304 was the calendar published, with its permissive and prohibitive regulations[19]. C (_comitialis_) means that the day so marked was one on which the _comitia_ might meet[20], and on which also legal business might be transacted, as on the days marked F, if there were no other hindrance. The total number of days thus available for secular business, i.e. days marked F and C, was in the Julian calendar 239 out of 365. N, i. e. _nefastus_, meant that the day so marked was _religiosus_, _vitiosus_, or _ater_; as Gellius has it[21], ‘tristi omine et infames impeditique, in quibus et res divinas facere et rem quampiam novam exordiri temperandum est.’ Some of these days received the mark in historical times for a special reason, e. g. a disaster to the State; among these were the _postriduani_ or days following the Kalends, Nones and Ides, because two terrible defeats had occurred on such days[22]. But most of them (in all they are 57) were probably so marked as being devoted to lustrations, or worship of the dead or of the powers of the earth, and therefore unsuitable for worldly business. One long series of such _dies nefasti_ occurs Feb. 1-14, the time of purification; another, April 5-22, in the month occupied by the rites of deities of growing vegetation; a third, June 5-14, when the rites of the Vestals preparatory to harvest were taking place; and a fourth, July 1-9, for reasons which are unfortunately by no means clear to us.