Romulan calendar

• Units
  • Ewa (Romulan second) (ENT Novel: The Good That Men Do)
  • Siure (Romulan minute) (ENT Novel: The Good That Men Do, Beneath the Raptor's Wing)
    • Plural: siuren (ENT Novel: Beneath the Raptor's Wing)
    • Approximately 50 seconds (ENT Novel: Beneath the Raptor's Wing)
      • 12 siuren is equal to "a little over ten minutes" by that work
  • Dierha (Romulan hour) (ENT Novel: The Good That Men Do)
  • Eisae (Romulan day) (ENT Novel: The Good That Men Do)
    • Also known as a ch'Rihanturn (ENT Novel: Beneath the Raptor's Wing)
    • Between 1.2 and 1.24 days per eisae (ENT Novel: To Brave the Storm)
      • "Slightly more than four eisae" = "Nearly five Earth days" by reference
      • Original presumption 1.14 to 1.24, fine-tuned by calculations below
  • Khaidoa (Romulan month) (ENT Novel: The Good That Men Do, Kobayashi Maru, Beneath the Raptor's Wing)
  • Fvheisn (Romulan year) (ENT Novel: The Good That Men Do, Beneath the Raptor's Wing)
    • 11-12 khaidoa to a fvheisn (ENT Novel: Beneath the Raptor's Wing)
      • six khaidoa is "half a fvheisn or more" by that work
• Months
  • Tasmeen (ENT Novel: The Good That Men Do, To Brave the Storm)
    • At least twenty-one days (ENT Novel: The Good That Men Do)
  • Havreen (ENT Novel: The Good That Men Do)
    • At least eight days (ENT Novel: The Good That Men Do)
    • Immediately follows Tasmeen
  • K'ri'lior (ENT Novel: Beneath the Raptor's Wing)
    • At least 44 days (ENT Novel: Beneath the Raptor's Wing)
    • Shortly after Tasmeen (ENT Novel: Beneath the Raptor's Wing)
      • "More than a full fvheisn" between Tasmeen 11 of the previous year and K'ri'lior 10 of that reference's
      • Havreen established as immediately after Tasmeen; possibly month immediately after that
  • et'Khior (ENT Novel: Beneath the Raptor's Wing)
    • At least 4 days (ENT Novel: Beneath the Raptor's Wing)
  • K'ri'Brax (ENT Novel: Kobayashi Maru)
    • At least 40 days (ENT Novel: Kobayashi Maru)
    • "A few khaidoa" after Havreen (ENT Novel: Kobayashi Maru)
      • Between February 23, 2155 (Coridan Prime attack, late Tasmeen/Havreen), and K'ri'Brax 29 (ENT Novel: Kobayashi Maru)
    • February 21, 2155 (late Tasmeen/early Havreen) "two khaidoa" before K'ri'Brax 33 (ENT Novel: Kobayashi Maru)
      • First event Ehrein's rescue from Rator II, Chapter 38 of The Good That Men Do
    • "Some three khaidoa" between Tasmeen 5 and K'ri'Brax 33 (ENT Novel: Kobayashi Maru)
      • Between Cunaehr's death, chapter 1 of The Good That Men Do, and chapter 11 of Kobayashi Maru
  • re'T'Khutai (ENT Novel: Beneath the Raptor's Wing)
    • Apparently immediately following K'ri'Brax by correspondences
    • At least 3 days (ENT Novel: Beneath the Raptor's Wing)
  • Khuti (ENT Novel: Beneath the Raptor's Wing, To Brave the Storm)
    • At least 11 days (ENT Novel: Beneath the Raptor's Wing)
• Correspondences
  • Nearly three fvheisn between April 17, 2152 and early February 2155 (ENT Novel: The Good That Men Do)
    • Between "Minefield" and chapter 4 of The Good That Men Do
  • Mid-November 2154 "the previous fvheisn" from July 2155 (ENT Novel: Kobayashi Maru)
    • Between "Babel One"/"United"/"The Aenar" and chapter 11 of Kobayashi Maru
  • Late-January to early-February 2155 "more than a full fvheisn" before February 11, 2156 (ENT Novel: Beneath the Raptor's Wing)
    • Between chapter 4 of The Good That Men Do and chapter 39 of Beneath the Raptor's Wing
  • Tasmeen 5, year of D'Era 1178 > January 24, 2155 (ENT Novel: The Good That Men Do)
    • Year derived from calculations, see below
  • January 30, 2155 > Tasmeen 11, year of D'Era 1178 > February 3, 2155 (ENT Novel: The Good That Men Do)
  • February 9, 2155 = Tasmeen 21, year of D'Era 1178 (ENT Novel: The Good That Men Do)
  • March 3, 2155 > Havreen 8, year unknown > March 21, 2155 (ENT Novel: The Good That Men Do)
  • July 13, 2155 > K'ri'Brax 29, year unknown > July 14, 2155 (ENT Novel: Kobayashi Maru)
  • July 14, 2155 > K'ri'Brax 30, year unknown > July 15, 2155 (ENT Novel: Kobayashi Maru)
  • July 15, 2155 = K'ri'Brax 31, year unknown (ENT Novel: Kobayashi Maru)
  • July 16, 2155 > K'ri'Brax 33, year unknown > July 17, 2155 (ENT Novel: Kobayashi Maru)
  • July 22, 2155 = K'ri'Brax 37, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • July 22, 2155 = K'ri'Brax 39, year unknown (ENT Novel: Kobayashi Maru)
  • July 22, 2155 > K'ri'Brax 40, year unknown (ENT Novel: Kobayashi Maru)
  • July 30, 2155 = re'T'Khutai 3, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • November 8, 2155 = Khuti 11, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
    • Year by calculations below
  • February 11, 2156 = K'ri'lior 10, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
    • "More than a full fvheisn" after Tasmeen 11, 1178 D'E above
    • Must be only barely into 1180 D'E, with Tasmeen 11 near end of 1178 D'E?
      • Yet Khuti 11 93 days (75-77.5 eisae, about 1/4 a fvheisn) earlier still in 1180
      • Possibly just weird turn of phrase
  • March 11, 2156 = K'ri'lior 39, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
  • March 14, 2156 = K'ri'lior 42, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
  • March 15, 2156 = K'ri'lior 43, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
  • March 16, 2156 = K'ri'lior 44, year of D'Era 1180 (ENT Novel: Beneath the Raptor's Wing)
  • March 18, 2156 = et'Khior 2, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • March 20, 2156 = et'Khior 4, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • May 19, 2156 = T'ke'Tas 13, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • June 20, 2156 = T'ke'Tas 43, year unknown (ENT Novel: Beneath the Raptor's Wing)
  • September 29, 2156 = Early in the month of Khuti, year of D'Era 1181 (ENT Novel: To Brave the Storm)
  • June 24, 2159 = Tasmeen 6, year of D'Era 1183 (ENT Novel: To Brave the Storm)
• Calculations
  • Eisae = [1.14,1.24] days
  • February 9, 2155 = Tasmeen 21, unknown year, thus Tasmeen 6 on January 21-23 (given 1.14-1.24 days per eisae)
  • Tasmeen 6, 1183 D'E = June 24, 2159
    • Thus 1615-1617 days before day repeat
    • Between 1302.419 and 1418.421 eisae
  • Early Khuti 1181 D'E = September 29, 2156
    • 998 days between Khuti 1181 D'E and Tasmeen 6 1183 D'E
      • Between 804.839 and 875.439 eisae
      • Thus between 269 and 438 eisae per fvheisn extreme ranges (if Khuti and Tasmeen last and first months vs. first and last as extreme cases)
  • Khuti 11 ?? D'E = November 8, 2155
    • 326 days between Khuti 11 ?? D'E and Early Khuti 1181 D'E
    • Between 262.903 and 285.065 eisae, thus must be a single fvheisn
    • Thus fvheisn 269-~290 eisae (variance on upper bound depending when "early Khuti" actually is)
      • Odd length of year given many khaidoa with ~35-40 eisae, confirmed 11-12 khaidoa/fvheisn
      • Alternating extremely long and extremely small?
    • Thus Tasmeen 6 in 2155 must be 5 fvheisn earlier
      • 1302.419 eisae / 290 eisae = 4.5 fvheisn, smallest possible value
      • 1418.421 eisae / 269 eisae = 5.3 fvheisn, largest possible value
    • Thus Tasmeen 6 in 2155 between 1345 and 1450 eisae before Tasmeen 6 in 2159
    • Thus eisae no less than 1.201 days
    • Thus fvheisn no more than 283.6 eisae (1418.421 eisae = 5 fvheisn)
  • Check against correspondences
    • "Nearly three fvheisn" between April 17, 2152 and early February 2155
      • Between 1020 and 1033 days depending on exact position of latter
      • Thus between 822.58 and 860.83 eisae
      • 822.58 eisae / 3 = 274.19, 860.83 eisae / 3 = 286.94; nearly means must be below
      • Fits 269-283.6 range
  • Note that explicitly stated eisae/day equivalence in To Brave the Storm contradicts tendency in prior RW novels to increment Romulan date and Earth date in sync
• Overall summary: references to Romulan calendar are fairly inconsistent in 22nd century ENT novels, and just use CLB's calendar from DTI