STRICT ANCHOR — only what stands on its own account, plus physics
Lu (annals' day-names + visibility): mass at (-721, 49) = 1.0000; top -721/49 24/21 1.0000; -667/33 21/15 0.0000; -775/5 19/14 0.0000
Ptolemy (own planets + own declinations), support ±300 years at one-day steps (219001 epochs):
  planets only     : mass within 1 d 0.0045, 30 d 0.9830, 1 y 0.9834; 95% band [-3, -2, 2] d; hits histogram {0: 207649, 1: 10846, 2: 490, 3: 14, 4: 2}
  precession only  : mass within 1 y 0.0150, 30 y 0.6941; 95% band [-18371, 1674, 20046] d
  both             : mass within 1 d 0.0046, 30 d 0.9972, 1 y 0.9975; 95% band [-3, -2, 2] d
  top epochs (both): -3 d hits 4 χ² 14.1 0.4883; -2 d hits 4 χ² 14.1 0.4881; -10 d hits 3 χ² 14.1 0.0023; -9 d hits 3 χ² 14.1 0.0023; -8 d hits 3 χ² 14.1 0.0023
  record                                                         our calendar    days ago  P
  Nabonassar 1, Thoth 1 (the epoch)                              2773·12·25       1012657  0.4883
  Mercure Nab 881 Epiphi 18 → sur les 184 ? : du taureau         1892·3·15         691140  0.4883  no landing 0.005
  Mercure Nab 886 Epiphi 2 → sur les 17% : des gémeaux, en arriè 1887·2·26         689331  0.4883  no landing 0.017
  Jupiter Nab 880 Épiphi 1 → 23“ 11° du scorpion                 1893·2·27         691522  0.4883  no landing 0.002
  Saturne Nab 886 Méchir 6 → à la brillante hyade, paroissoit su 1888·10·21        689477  0.4883